drscottsmith

Shortly after pulling the pod and instrument cluster to try to repair, my headlights decided to stop working one evening.

The good news is that they failed in the raised position - so if the lights ever decided to work again at least they would be raised.

Parking lights work fine - neither high nor low beams work and lights will not retract.

I am starting with the switch, as I have seen that it is sometimes at fault. Decided to take it apart.

Will continue to post here moving forward. Could not find anyone who had done this so I figured I would document for others. Here are the disassembly pics.

-scott

drscottsmith

There are two tabs on either side that hold the two parts of the switch housing together. Gently pry from under one side at a time to release the tabs.

The bottom (white part) of the switch (with the wire connection tabs) is now free from the top section.

Be careful of the springs. There are 6 springs inside of this one switch.
Two protrude from the bottom of the switch - they are larger and fit "inside" one another.
There are three contact assemblies around the barrel of the switch. Two are triangular in shape and one is a bar. All three have a small spring behind them.
The last spring is in the switch barrel above the contact assemblies.

NOTE: There is also a small ball bearing that is just dying to fly out when you separate the switch barrel from the housing. Ask me how I know.

So plan is to clean the contacts for the switch carefully and then reassemble.

AirtekHVAC

I took mine apart too....not so carefully...all the crap popped out!

drscottsmith

Well I have news - but it is not quite as good as I had hoped.

So the contacts on the switch cleaned up nicely with a little DeOxit.

When I started to reassemble though, disaster struck, and I broke one of the mounting tabs.

Lesson learned: As with just about everything on these cars, the switch is a bit over engineered. The tabs that hold the two parts of the switch barrel together are DIFFERENT SIZES to ensure you put it together correctly. I didn't catch this at first and in trying to force it to click I broke a tab. Not sure if there is any way to salvage at this point.

More to come - anybody got an extra working switch?

-scott

Alan

I suspect this may not have been the problem. I think I'd have just tested the switch function before disassembly.

You can also achieve quite a bit of cleaning by just injecting switch cleaner and mechanically operating the switch while flushing - then use a contact promoter to finish up (de-oxit/stabilant etc). Used switches are relatively cheap and generally reliable, new is also available (same all years).

Alan

drscottsmith

Well the good news is a got my headlight switch reassembled and it is operating just as it was before.

Like Alan - I am sure it was another culprit and I should not have messed with taking the switch apart - just checked continuity on it.

So now moving on to the relay. It is disassembled, as a few have suggested that even if working, there is a potential need to do some preventative cleaning on it and it comes apart/goes together much easier than the switch.

Here are some pics of disassembly. It is surprisingly clean on the inside - no signs of burning or pitting on the relay contacts.

I may have a wiring issue somewhere. Fuses are good in all related circuits.

RECAP:
1) Dash lights (IP) all come on with headlight switch in both parking and headlight positions.
2) Parking lights and fog lights work fine.
3) Headlights are currently raised and DO NOT work in either low or high beam
4) Headlights will not retract with ignition on

As part of this project and to help me better understand the CF diagram, I am going to write a Theory of Operation for our headlight system that may help others along the way - unless I can find one. I have not come across one yet.

Thanks -

-scott

Alan

Here is a version I wrote years ago that is a small part of a bigger document:

Alan

AirtekHVAC

Scott...I have one, I believe, if you need it. I have found some neat bonding cement that I have used on these switches, and it has held up very well. Give me a buzz or text tomorrow and we can discuss.

Btw #30 lights would go down, but not up....ended being corrosion on the terminals at the motor, under the rubber plug.

Wisconsin Joe

I haven't had to dig into my headlight system (yet), and I'm often wrong with stuff I haven't had my "hands on", but I suspect the motor as the culprit.

Keep in mind that there are "tracks" in there that determine 'up', 'down' and 'on'.

Similar to the wiper motor, there are circular copper traces with gaps. When on, power goes to the 'up' one, which has a gap when the lights are all the way up. There's also a part that only connects when the lights are up that allows them to illuminate.

Similarly, there's a trace for 'down' that has a gap at the bottom.

Since the lights go up, but don't illuminate or go down, along with how nice the relay looks, I'd take a good look at the motor assembly.

Alan

BTW the write up I posted is for the S4+ type system ('87-'95). The Pre-S4 system ('80-'86) is similar but has only 3 embedded relays in the HL relay rather than the 4 embedded relays for the S4+ system. This is due entirely to the motor configuration where the pre-S4 system always runs in one direction (so reverse drive switching is not needed). The tracks in the motor also have diodes integrated. General operating theory is much the same - however the motors & relays are quite incompatible between the 2 versions.

If you could create a similar write up for 1980-1986 cars that would be a useful addition.

Very early cars ('78-'79) have separate headlight relays (no double can relay) - its relatively easier to figure out how these work directly from the wiring diagrams.

Alan

drscottsmith

Alan this is exactly what I was envisioning. Thank you for the support in creating a version for 80-86 models.

Appreciate everyone else's support as well. I will get into that motor assembly and hopefully get everything working.

thanks again all

-scott

928NOOBIE

Here's a crazy idea...buy a new switch and relay and take the time you saved and drive the car.

drscottsmith

As I continue to troubleshoot this issue...pics included below. Pulled the headlight motor. Connectors were very clean (I was hoping for a lot of crud). Wipers in motor drive assemble were very clean - again hoping for a ton of gunk). Reinstalled everything and same issues - here is where it gets weird.

coming home lasts afternoon with the headlights all the way on and no fogs, flicked the high beam switch and the dash indicator came on. Pulled closer to the car in front of me and sure enough, headlights are working great.

got home and left everything as is to check and everything is working correctly. Fog interplay with headlights works correctly and all looks good.

turned light switch off and everything went off, but lights did not retract and then they would not come back on.

do these new revelations point to anything??

thanks

-scott

drscottsmith

The Deputy

Buy yourself a new/used (but tested) headlight combination relay from 928 International. My malfunctioning relay looked just like yours, no visible issues...but it did the same thing as yours.

Brian.