Turn Signal and High Beam issue solved!
The turn Signal issue is a two part problem - and both issues are really easy to go un-noticed if you haven't had to battle with a old turn signal switches before. I will say however, that Datun's design for the way these work is far better than the GM and Ford ones!
Once the Horn Button is removed that the steering wheel - we can access the switch. There is a small lock ring that holds it on. As soon as I seen this - I knew part of the problem!
I have this set of snap-ring pliers and love them. It is made by OTC.
That red arrow is point to where there should be a rectangular contact bar. It is missing here. The two small rectangular slots are where the "ears" go, and the round hole retains a small spring. I will be making a replacement.
The missing contact basically rests on the inside two round contacts, and then connects the outside ones in pairs (denoted by the red scribbles.)
Without that piece, there is nothing to apply the 12v power to the rest of the blinker system.
The next step, was to verify the rest of the system was working. I didn't take a pic of the "before" but those 4 round contacts looked clean - the key term is "looked" - copper as it ages and oxidizes gets a pretty non-conductive coating on it. Using a test lead between the two sets of contacts failed to actually connect, and as you can see my PowerProbe was registering zero volts despite being stuck on both the center contacts (which should be +12V) So time to clean them up.
I have a matco set of small electrical connector files - they are awesome!
In this pic - if you look at the other side of the switch you will see a large flat contact - at the 4 o'clock position that is in the background, that looks fine but it also had the same oxidized "coating" so you can see the difference between cleaned and what looks clean.
I also tested the flasher modules. These basically have a 12V in, and then the other terminal goes to the load (in this case the lights) that is marked with "L" on the bottom. These basically work like a controlled kinda-sorta "short" - the heat/resistance generated by the 12V being applied to the Load causes a tiny contactor of dissimilar metal to bend breaking contact - then it cools and returns. Modern replacements can use a relay and a bit of circuitry to do the same. This is also why the old style doesn't work with LED lights - there isn't enough resistance to generate the heat needed for the little contactor in there to do it's thing. Here I just used the 12v contact and the contact going to the rest of the system to quickly check them.
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After that if we connect the center contact to and outside - we get a functioning blinker. This tells us our diagnosis was correct and the rest of the system is good. Here is a video :
https://flic.kr/p/2mkKzPG
The issue with the brights is the contact (mentioned early in one of the pics, and the contact on the moving part of the switch.
The red arrow is pointing to the contact that triggers the high-beam relay by apply ground. As you can see I already too the cleaner to it. The Blue arrow is the horn contact - which is working, but we will clean it anyways.
The red arrow in this pic is what pulling on the high beam lever moves to apply ground to the contact in the previous switch. Notice it isn't shiny so we will clean that to ensure good contact. Also we will be making sure it is adjusted to make good contact - as these over time will lose the ability to do so. I used the PowerProbe to test the rest of the circuit - and it works correctly, so once it is re-tensioned and cleaned we will have a working high beam switch!
I am going to pick up the stuff to make our missing contact and find a suitable spring tomorrow, then I will update this with the reassembly and final test and we will move along to figuring out the gauge issues!
Untitled by Paul Taylor, on Flickr
