desertdatsuns.net

AZhitman posted looking for someone to re-wire his cool 411 wagon, so we worked it out and the car is in my garage getting the work done!

I had taken a "break" from the car stuff for the last year and a half after a career change (Quit the hot-rod shop - hopped over into healthcare I.T.)
As for the reason of the career change - I realized I was getting too old to be working huge hours for little pay, no time off, zero benefits - and unfortunately was a victim of my own success in that I was handling 75% or more of the workload building the cars at the previous employer. Passion can only account for so much as the invincibility of youth(ish) fades. The opportunity arose at my current employer and I couldn't say no. Higher pay, actual PTO, sick time, zero stress, and great benefits.

AZhitman's need came at just the right time as I was starting to do work on my days off (tues-thurs) to satisfy the "fix old stuff" bug.

So without further jibber-jabber - here is the first update into this project. This isn't an advertisement - hopefully this thread will give some insight and and answer some questions about the process of doing a re-wire of a classic car. I am one of the few people with a specific disorder in that I enjoy automotive electrical.

So here is the victi...er I mean Wagon. I gave it a quick bath before work began.


After studying the wiring diagrams for a few minutes, I start at the very front and will work my way back for removal of the stock harness. Also I will keep a list of anything that I need to order supply wise if I don't already have it. The foam pad (this one is from matco) is a lifesaver!



Most of the connectors / terminals / etc are pretty standard fare as evidenced by the headlight connectors. The new ones came with the wiring kit - but I will de-pin these as I prefer to have the least amount of splices / connections as possible and will crimp on the appropriate terminal when I run the new harness.



The old battery cables and terminals will be replaced with nicer, new ones. Battery terminals are often overlooked as maintenance items. Also you can see where the insulation has been pulling away from the actual terminal. This is a side effect of age (Insulation shrinks) and use. I will use a different style and method that is more resistant to these effects, I will post how I do these and the tools needed in a future post.



I removed the marker light assemblies because the lenses were stuck, and I will be cleaning / replacing the wiring. I have the correct "pin head" terminals for this style marker light. When I get to re-wiring these I will make sure I get a picture of them as they are neat and most people don't realize they are available. Also, friends don't let friends have electrical tape covered anything so I will remove and clean all the tape and residue.



Here is another thing to look out for. The grey gaskets used on these marker lights/lenses over time basically turned into glue. The lenses were not interested in coming off so it took the careful application of heat and wiggling to get them off without damaging them. I have seen countless people try to pry them off around the edges or jam a screwdriver in the screw hole - which 99% of the time ends up on a broken lens.



With the front grill removed - we can access the electric cooling fans. These fans were also loose and had about 1/4 inch of play on/off the radiator. I will address that as it not only an cause annoying noise - but the rubbing / banging into the radiator can damage it. I will use a weather-pak style connector on this part of the wiring as it is weather proof and these fans are a high-amp draw. Electric cooling fans draw the most power at start up (as much as 20 -30 amps) before settling down once the reach operating RPM (these probably draw 5-8 amps once running.) I will use a new relay & holder for this circuit.



Here is the relay and fuse for the fans that we will be replacing. There is probably nothing wrong with these - but given the cost of a new one it doesn't make sense to reuse it when everything else will be new.



Here are our horns, located under the core support. These have also wiggled their way loose so I will address that. Also, those insulated crimp connectors will definitely find the trash bin. There will be none of those things in this car's electrical system anymore.



Behind the battery we have several relay. These are for the various lights, horn, etc. These will be replaced by modern relays, however not in the stock locations as they would look out of place. The long one is for the headlights, short one is for the horn.







This appears to be some sort of solenoid - complete with a manual test button on top.



Once those have been removed and disconnected we can continue on with removing any other connections under the hood to facilitate removing the engine bay harness.

Here is our old fuse panel. Bye!



The ignition coil and ballast resistor (which will be tested, and replaced if needed.) We also see more of those pesky insulated crimp connectors that I won't be using.



Here is our brake pressure switch for the tail lights. This will be tested, and replaced if needed.



Here is the old fuse panel, and the new. The new one will be installed under the dash, inside the cabin of the car. This will keep the panel away from the elements. Also, in a turn of luck there is already a hole in the upper corner of the firewall under the dash. I can pop out the plastic/rubber plug install a new one and route my new harness through there. Less extra holes drilled the better. The new panel already has the turn signal flasher and a relay installed.



There is a nifty little underhood light chillin' over on the driver's side. I will see if it works - and if not, pretty sure we can get it working.



Now that the old fuse panel is out of the way, we can see up in the corner there is the rubber grommet/seal were the harness makes it's way inside.



I will remove the little under-dash tray to gain access to the harness inside.



In the upper corner under the dash we can see where that harness is coming through. Obviously it won't fit through the firewall with all the plugs. Time to do some depinning.



For this task we will use my depinning toolkit. This set I bought from Cornwell several years ago - and it is really nice. However, there are plenty smaller/cheaper sets out there. If it is something you are using just once - a cheapy set will do the job. If you think you will use it more than once - spend a little extra and get a nicer set. There is a difference, trust me.



The male side of these connectors you can use a teeny flathead to depin as I am doing here. If you look up it's skirt you can see the little nubbin' you have to push down.



The female side you can actually see what needs to be done through the connector. Here I am using a depin tool and you can see how it works.



A little while later, we have depinned all the connectors. They are still in reasonable shape - so if I decide to reuse them I will throw them in the ultrasonic cleaner.

Once all those connectors are out of the way, I carefully pushed the grommet out towards the front of the car, and then on the engine bay side pulled the harness through.



Here is our complete engine bay and front lighting harness out of the car. We will refurbish and reuse the through the firewall grommet - but on the other side. Everything else will be bagged and tagged, and no longer used.



Here is a picture of the parts removed so far. It is always a wise decision to remove parts, instead of fight to work around them. I use this little cheap labeler, I just have to remember to wash my hands before using it as it doesn't deal well with dirt. This little thing will also be involved in labeling some of the new wiring going it - I have a nifty system for that I will show later. I have a couple of these little cheap fold-up tables. They are great for garage use.





Here is the battery area, after all the wiring was removed. I hit it up with some degreaser and gave it a quick clean. Other than the wiring that will be going to the ignition coil and the ballast resistor - there will be no visible wiring here. This way the engine bay will look less cluttered and won't distract from what is the real attraction, the engine.



The next update will be removing the instrument cluster, and dash harness. I will work my way back to the tail lights. Once all that is done - the real fun begins and the new stuff will start being installed. I will show the wiring loom I prefer, and the tools needed to crimp on the terminals. I will show the different types of heat shrink I use, as well as the labeling system.

Now it is time to start removing the cluster / dash harness.



The cluster is held in by three studs/nuts. Pretty easy to remove. There is one large circular connector on the back. The circuit board looks in good shape, but I will be giving it a good cleaning before it goes back in, and testing all the lights.

The goldish colored component above the speedometer is a voltage regulator. These were also common on a variety of American cars of the same period - usually of the mopar variety. These are usually a points/breaker style regulator and not solid state. I will test this one - and if it is a little goofy I will make a solid state one (pretty easy task.) When you test them with a multimeter they actually "blink" voltage on and off - and the duration of the "blink" is how it regulates the amperage going to the fuel gauge.



Being Arizona - dust and dirt gets everywhere! I always try to spend a couple minutes cleaning where I am working. Makes the job a bit easier. I will also re-glue the under dash insulation while I am in there since it is a bit floppy.




A few other pics of the dash /interior stuff.

Door switches - as you can see these are pretty crusty so they will go in the ultrasonic, get cleaned,lubricated, and tested before reinstallation. Since this circuit operates on ground but is "always on" it is common for these to get crusty, stick, and cause a battery draw.



A ground attached to a bolt holding the hood release. I see this all the time, easy to access fastener makes it an easy target for a ground. The problem here is that it is on a painted surface, going to another painted surface - so it is relying on the bolt to supply ground. This can be problematic. I will run all the ground for the dash harness to a more appropriate place, with metal-on-metal contact and protected with some dielectric grease.



Here is the entire dash harness removed from the car.



Now that that is out, lets move to back for the tail lights and fuel sender harness, and there was a bit of a surprise in store.


Removed the spare tire, as under the plate that holds it in - is access to the fuel sender (smart thinking Datsun!)



Here is the back of the tail-light assemblies. There is four nuts that hold them on. The inside and middle are easy to get to - the outside ones you have to contort a bit to get to.



These electrically are connected to more of the white connectors.



The rubber gaskets that seal the tail-lights are moderately brittle so care is needed to "break" the seal. I use this trim removal set from Cornwell. The plastic tools don't mar.





Here is a tail-light assembly removed - it will get cleaned and tested later. Notice how the rubber gasket is showing it's age and exposure to the AZ heat. That is why it pays to spend a little extra time and be careful.



As usual, a quick cleanup



With the spare tire mount / access panel off and a quick cleaning we can see the fuel sender wiring. Pretty typical and the wiring will replaced.



Which leads us to the surprise. Typically on most cars the rear harness / etc is ran inside the car to protect it from road grime, weather, moisture, etc. On this car the harness was ran underneath the car - allowing moisture, grease, oil, etc to saturate it.

The wiring at the very rear where it enters the "trunk" looks typical



But as the harness travels further up - it shows why most manufacturers ran this inside the car. Where I am pointed you can see the darker areas of undercoat that have had grease slung on it - and so has the wiring.



Here is a close up of the harness, showing how much moist (hehe) gack has accumulated over the years. This will slowly but surely compromise the wiring underneath.





Here is the whole rear harness removed from the car. I will be running this inside the car when I start installing the new stuff.



Here is about 90% of the wiring of the car removed :




The next update will be exciting - I will be testing various things, inspecting things, and then - laying out how the new stuff will be installed and starting the process of putting in the new fuse panel and harness!

Rainy Day Update.

As I still wait for my wire order to show up..... lol.


But here is a few little tasks that are getting done.

The stock ignition switch only had a couple positions and probably is pretty low in amp-handling ability. I have a bunch of these generic GM style ignition switches laying around and this is a good update as now the car will have an off / acc / ign / start typical sequence and these can handle plenty of power and will facilitate later upgrades if the car goes that way.





The only issue is the hole in the dash of the datsun is too large - but I made a centering shim. This fills the gap.





I then mounted the fuse panel. Mounting it at a slight angle drives my OCD nuts - but this was the best way to mount it high enough you don't see it when looking in the car's driver compartment. I used this Cornwell Riv-Nut tool (made by astro) so that way I could use two M5 machine bolts to hold it in. I looked at the receipt and realized I have owned this tool for over 5 years - and it has never let me down.

This tool is a steal of a deal for around ~80 bucks.



I used a automatic center punch tool and my Milwaukee right angle drill (best drill ever) to drill the holes for the fuse panel.



First riv-nut in, I will then mounted the fuse panel and figure out where the second one needs to go.



Fuse panel mounted, up out of the way but still with reasonable access to the panel.





With the fuse panel mounted I can start separating what goes where. This wiring kit is very basic, and is made to only replace the factory fuse panel and then connect to existing other wiring. I will be making new harness for everything as to avoid any issues later on from corroded/old wiring.



I started terminating the wiring that will run to the ignition switch. This also required the addition of a wire that runs to the battery - and to make sure we have enough amp supply for future upgrades it will be a 10ga wire. Here is how I label the "sub harnesses" - I will use a section of black heat shrink and my label maker. Since labels never stick to wires for long - I slide a piece of clear heatshrink over it. This ensure that it will not fall off and will last.





Now that is done, I will start work on the cluster. That begins with figuring out what wires do what, and testing the voltage regulator and lights.

Here is the little regulator I point out in a previous post. This basically supplies the gauges with ~5v. It is a points/breaker style regulator so when power is applied it rapidly on/offs as a way to drop the voltage. You can see it is labeled - and the "IGN" is our 12v source, the little mounting bracket supplies ground, and the other spade is our output. I will use my power probe and multimeter to apply power and test this unit.



As we can see, it is about 4.2 volts which is fine. This shouldn't cause any issues and while it was operating I seen voltages between 4 - 6. If you notice my meter is set to AC voltage instead of DC. Since this unit operates by "blinking" the voltage - the auto-range multimeters won't pick up the fluctuations in time to give you a reading. By using AC you can get a reading.



Testing the bulbs and holders. These always need a bit of a cleaning - so the sockets go in the ultrasonic. The PowerProbe is one of the best electrical tools you can own. This one is a PowerProbe 4 - and in addition to being able to apply positive or ground, it has a built in auto-resetting circuit breaker, and several modes. It can even measure injector pulse-width.



Here is the back of the cluster all reassembled. The stock plug I will reuse. Since it uses some difficult to obtain pins I will be reusing a short length of the wiring out of the plug. Instead of soldering/crimping these wires to the harness going to all the places it needs to - I will be installing a secondary connector here. Reason being is that the factory circular connector takes quite a bit of effort to remove and this circuit board isn't getting any younger or sturdier. Using a "secondary" connector will allow the cluster to be disconnected safer, without risking damage to circuit board.



I cleaned the circuit board with some glass cleaner and applied a thin coat of dielectric grease to protect the exposed copper parts.

This is the little ultrasonic cleaner I use. Just some water and simple green does wonders. For example, I cleaned the door switches - as they were quite crusty as I showed a few posts up. This little unit is also heated - which is nice.



After a few minutes in the ultrasonic - I will then transfer them to a "pickle jar" full of alcohol to displace the water. These little plastic "pickle jars" are awesome - they even have a built in strainer.



And here is the result - much, much better. All the green corrosion and dirt/dust is gone. These tested OK on the multimeter so I will use some dielectric grease on them - and reinstall!



Next update will be the connectors for the cluster, finishing the dash harness, and making the headligh/marker/fog/fan/etc harness as supposedly my restock shipment is coming today or tomorrow.

Let's make a front lighting harness!!

I always scribble down a primitive diagram - just to figure out how many runs / colors of wire I need. Usually I will stare at this a bit, and realize I forgot something (I did in this scribble - I needed one more wire for the running lights.) and that gives me a good idea of where to start.

I typically will run the light/horn/turn harness by itself, then will run the engine harness by it self - instead of it all being clumped together in one mega-uber-harness.



So now that I have a rough sketch of what goes where lets get tangled up in some wires.

I have owned several wire dispensers over the years - and none work as good as the ol' trusty egg crate. You can feed the wire through the holes in it, and carry it around super easy - and it can hold quite a bit. I recently loaned this out to a friend - he just stopped by, grabbed it, used it, and returned it. Self contained tangles.



Here is our bunch of wires. Generally the way I gauge length is I roll out the wire that will be the longest and roughly route it where it needs to go. I then make every other wire that is on that side the same length, and for the other side I subtract however long the difference it is plus a few inches. It is always easier and better to shorten wire , then have to extend it.

This is also one of the few times I will use electrical tape - and that is just to keep the wires bunched together for when the loom goes on. I tie one end to my tool box and arrange it.



As I mentioned above, I go from the longest to longest, here I am setting the rough group of wire into place and I just start from the furthest point of where it will have to reach. The under dash section will obviously be tucked up in the dash, and secured - not all dangly like in the pic.



The factory harness ran on the passenger side of the bay, I am changing that to run it on the driver side since that is the side the fuse panel is on, and that will keep the already cluttered by the battery passenger side a little cleaner. I am using an existing hole that also exists on the passenger side - which will allow me to reuse the grommet - just on the opposite side.



I also will mark where the loom will be passing through the firewall so that way I know where to terminate the loom.



A simple trick I learned a long time ago. Once you lay the wires in place, zip tie them to something before you start running them to all the stuff. It really sucks if you don't and do not realize things have moved while you are pulling and moving wires - and trimming them....lol



Here is our gaggle of wires.



Now time to start putting them where they will live and taping them together in bunches that will co-exist.



Here we have the high beams, low beams, marker lights, fog lights, and horns roughly where they need to be. The harness won't be ran on top of the radiator, in case anyone was wondering haha.



Once everything is grouped and trimmed - time to gingerly pull it all out for the looming process. Here is most of our lighting wiring all grouped.



For melting heat-shrink this is my favorite tool. Mini Butane torch from PowerProbe. In a pinch it can be used a soldering iron.



The loom I am using is this braided stuff called "power braid." It looks nice, is reasonably temperature resistant, and is a pain in the butt to work with. The secret to this stuff is to think way ahead.



The heatshrink you really want to use with this is the kind with the built in adhesive. This glues the braid to the wires and to other braid. This is important as if you use standard heat shrink it will move around and your loom will slip out, and it will fray into an annoying difficult to fix mess. Ask me how I know......

I generally operate on the start by sliding on the biggest loom you will need and then the smaller branches. You also want to slide your heat shrink over the loom right after you run it. If you wait till you have all the little sections of loom in place, then try to slide all the heatshrink into the places you need it - you will have a bad time.

The little black wire proudly escaped the loom will be a ground for our headlights. There are three. Two just like this one, and then one that is at the other end of the harness. Always a good idea to err on the ground side in term of "how many."




So there is a mini-update. I am going to resume looming this harness, and then start on the rear one. It will be much simpler - just much longer.

Rear harness fabrication!

As mentioned earlier, the factory rear harness was ran underneath the car - exposed to the elements. This I would be willing to bet is the cause or a major part of the cause for the re-wire.

I ran the harness under the carpet / rear seat inside the cabin of the car to eliminate the wiring from being damaged.

Removed the rear seat :



Once again, I ran one wire that is the longest run (Driver side tail-light) and cut all the other wires needed to the same length :



When crimping connectors - the right tools is important. The rear harness will be using a 6-way connector to connect to the dash harness (like factory.)





Here is the connector, and the label when completed.



Here is the harness making it's way to the "trunk."



One of the very, very original wires used are for the tail-light connectors. These are an odd one that I don't have. I tested them for continuity and they are fine. Then a quick bath in the ultrasonic cleans them up. I tested the connectors/old wiring/bulbs with the trusty power probe.




When I have to make a "butt" connection - I used non-insulated connectors. I also tend to use one size up as it keeps from pinching the wires and in this case - where two wires have to be on side it gives both wires a place to reside.



Here is our new wiring , spliced into our old wiring with heat-shrink covering our splices and connections.



Since we will have some wiring between two connectors that our loom will not fit over - an advantage of this kind of loom is we can "scrunch" it up, ziptie it back, and that will give us room to finish the connections. When done, cut the ziptie and it will sproing back to its normal length and if I remembered the heat shrink (I did!) we can finish the ends. Also, in the background is the notes I use to keep everything straight color wise, which will be typed up and go with the car for future reference.



Here is the passenger side wiring, it is a bit more complicated as there are several connections that require a 1 wire -> 2 wire splice.



Here is the harness between the two tail-lights loomed and done



With the rest of the tail-light harness and the fuel sender / license plate light harness loomed it is all "in place." the section that is loose in the picture will be secured along the top of the trunk lip so it is out of sight, and away from any snagging on things in the back.



Now with the front harness done, the rear harness done - all that remains is the "engine harness" that will power the coil, distributor, alternator, starter - and the under-dash connections!

As far as tools go , here is part of my crimper collection :

The Astro ratcheting crimpers are a great deal for ~90 bucks, and I bought the extra set of Jaws that do spark plug wires - which work way better than any other spark plug wire crimpers I have ever used. There is also a few plier style crimpers, the right angle set is particularly useful for hard to reach stuff, the bigger blue handled ones and the knipex crimpers are great for really small terminals.

Lighting harness installation and making the engine bay harnesses!


The garage has been pretty nice in the evenings , the humidity during the day makes it warmer so I have been working under the cover of darkness, lol.

The evap cooler I have , top temp in ambient garage, lower temp is out the cooler itself. Not too shabby!



I haven't used much solder on this car - as in the automotive environment crimp connectors hold up better to vibration. However, a few places I do choose to solder are when I want a small connection size that I won't get with a crimp. Also, I am hesitant to crimp drastically bigger sized on one end, and small on the other. They actually do make "step down" crimp connectors but they are limited on sizes. So the headlight connectors, I soldered. I always use a little "helping hand" tool and then to make sure the wires stay tightly together I wrap them in a single strand of copper, then solder.



I will then solder the wires together :



A good solder application will be shiny - if it is dull it is a "cold" joint and will fail.

On the subject of lighting, if you find that you need to replace the little "button" contacts in things like marker light assemblies - you can actually buy them from places like American Autowire!



Speaking of marker lights - if you recall from many posts up - the ones on the car were wrapped in gooey tape. I stripped off the mess, cleaned it, and used heat shrink to recover. Another advantage of the "marine grade" heatshrink with the adhesive built in - is you can heat it up, and pinch it around to take up any slack from drastically different diameters. The glue will seal it up!



I ran the front lighting harness down the same route as the factory hood release, using it's little tabs.



I ran the harness through an existing hole in the core support, with grommets (split, and installed with a bit of glue.) this hides it well and gets it out of the engine bay. The fan wiring will be on a similar path when I do it.




The fog light connectors are "bullet" style - and since I hate insulated connectors - I have these non insulated ones. These are super handy cause with a little tweaking they will fit a few different of the male sized terminals. Crimped, then I cover them in heatshrink (normal, not the marine grade.)



On a unrelated note, here is the gauge cluster connector as I mentioned further up. I did it this way as I intend on not having anyone pry the factory connector off the circuit board as it is getting fairly old and the stress on it will eventually break it. This way there is a easier connector to undo and you don't risk the cluster's circuit board. Also, the connectors I am using look a lot like the factory ones.



So now that the front lighting harness is in, tested, and working (woo, nothing caught on fire!) Lets move on to the engine harness.

This one is a bit simpler than the front lighting harness, but we still want to make some notes of what is what and where it should go. Here is my messy notes on what is what. Basically I figure out what wires need to go "out" and put a count. I then split it up into what will be loomed together, and what the factory colors are and what the harness colors will be. I compare this to the wiring diagram for the car, and then double check it on the car itself. This usually allows for no mistakes and no forgotten wires or headaches when everything is installed. I have been known to do this step twice (as you can see in the pic) just to further error check myself. Worst thing ever is getting things made and installed only to realize your forgot to run a wire! This will also be very handy when it is done and I make AzHitman an info sheet with what is going where and what color.



Now that I know how many wires need to be ran for the harnesses I am making I can lay them out roughly. You don't have to run them the exact way you are going to when the harness is finished - you can just lay them out roughly in the area they will be. I always make things a bit long - just in case. Once again, I am using electrical tape to bunch groups together.



After that, here is what we have :



After some arranging here is the "engine" harness laid out for looming :



The wiper motor harness is easy, and we will label it of course.



Here is the unterminated engine harness. This has everything we need for the coil/ballast, distributor, oil pressure, oil temp, reverse switch, brake switch, underhood light, fan relay trigger, etc.





The next update will be connecting everything under the hood to the new harnesses, and connecting it all under the dash to the new ignition switch, fuse panel, radio, and switches - then the final test!

Thanks for AzHitman for being patient - this has taken longer than I estimated due to a few reasons, but the end is near!

Update!

Paul, This is so refreshing to see you so thoroughly documenting your excellent work. I wouldn't have expected anything less . Seriously, really enjoyed reading every word tonight and looking forward to future installments. I know you said this was not an advertisement, but if you are taking other electrical work when you get done with the 411, I'd love your help trouble shooting a few issues on my Roadster (nothing major). Looks like you are making excellent progress.

Thanks for the compliment Randy!

I figured I would document this well since it would probably be a good rough guide, or answer a few questions that people have.

The 411 should hopefully be done in a week and a half or so. I hit a snag when I ran out of a couple colors of wire - and like everything it seems - low stock. Luckily the restock will show up to me on Wednesday and I can finish it up! I am making new headlight / tail light / etc harness as the Painless kit didn't include them.


Once it is done, I will message you and we can see about sorting out the roadster.

Speaking of wire - as a warning to those who do their own wiring work (I discovered this when a friend called me this week about some funny issues with his racecar) - he had bought his spools of wiring off Amazon. The issue here is that not all sellers (most it would seem) are upfront about what their wire is made from. Turns out many, many amazon sellers are selling CCA wire (copper clad aluminum) which is essentially aluminum core. I hadn't seen this stuff in a while till I looked at his car and recognized it - and then was shocked when I looked on amazon to see it being advertised as automotive wire.

The problem with this is that Aluminum is much more brittle and doesn't hold up well to vibration (like in a car....) The issue he was having turned out to be a combo-deal. He had a few broken wires - and then I noticed an increase in resistance on the longer runs. Turns out CCA wire is like 20% less conductive than pure copper. This wasn't playing nice with some of the sensors on his engine management set-up.

So make sure you are always buying TXL or GXL wire from reputable places. Locally-ish we have ProWire and otherwise you can order wire from Painless or American Autowire by the foot / spool.