Headlight Multifunction Problems

[JustA5.0]

Oh the joy of owning a fox mustang, soon this car will be all 2008 parts in an 87 shell

Anyways, I decided to do the GT foglight fix (corral) because it seemed easy to follow and I am by no means an electrical guru.
Prior to this, obviously foglights weren't working, headlights, parking lamps, taillights and all that worked. When I begun taking things apart the previous owner had cut one of the brown wires from the headlight harness (6-pin) and spliced it with the light/blue black wire from the foglight harness *shrug*. I got rid of this mystery and soldered the brown wire back together by itself. I suck at soldering and this was a tricky location to solder, so including this info incase it makes a differance. I installed the relay and inline fuse, double checked that everything was connected as in the instructions, and voila! no foglights or headlights, parking lamps/sidemarkers worked but no turn signal flash, and flash to pass was the only way to get the h/l on.

I searched various threads on here and it sounded like my problem was between the headlight and multifunction switches (r/y wire). Started doing some testing, voltage was ok throught the headlight switch, and the r/y wire at the m/f switch had 12volts. There is no voltage at the r/blk and grn/blk wires of the m/f switch, nor at the foglight harness (though it has been altered and my testing directions assume it's still in stock form). Also, the multifunction harness connector is fairly burnt at the red/blk and grn/blk terminals. Before I shell out $120 for a multifunction switch/turn signal stalk, is my problem really just the harness connector being melted? I would try the harness connector first, however the only place I found one was Rockauto with a 12 business day 'non-stocked item' shipping delay (the local parts stores didn't carry or never heard of it). I was planning to take the car on vacation before that.

Is there any other testing I can do to eliminate the m/f switch or harness as being faulty, or conlcude they are both faulty? With 12v indicated at the r/y wire here I'm thinking the harness still functions, on the other hand my wipers still work and so does FTP so it makes me think the m/f switch still functions.

sigh...

 

[Darkwriter77]

Check to see if there's any corrosion on any of the connectors and/or contacts of the switch where they mate. Just went through this on Frankenstang's notch a few months ago, swapping switches and so on, until I finally figured out there was some corrosion on one wire in there (can't remember which one right off hand) that allowed either parking lights OR headlights, but not both. Made a new headlight switch "plug" with a few female spade connectors bound together with electrical tape, and voila! Working headlights again.

You might be able to use a tiny screwdriver or a needle or something to poke in there and scrape at the contacts/connectors to scratch off any corrosion or goop of any kind that might be in there, get some bare copper or aluminum showing, and then poke it back together and see if that remedies the issue.

I've got a wiring diagram of the switch (when I get home from work tonight) that I can post up, if it would help ya'...?

 

[JustA5.0]

It was raining here before I had to leave for work today, so didn't get a chance to look more into it. I've gathered a few wiring diagrams, but feel free to post what you have it certainly will help.

Was your corrosion on the headlight harness connector or the multifunction harness side of things? My headlight harness connector is a little burnt but the Ford instructions I had for testing it showed to be all good on the voltmeter.

 

[Darkwriter77]

Actually, the corrosion I dealt with was on both the connector and the switch's spade contacts. I swapped out the switch at one point, then the new one started acting up because of the remaining corrosion on the connector.

Gotta make a note to myself to post diagrams when I get home tonight ... unless JRichker beats me to it...

 

[JustA5.0]

Update:
After my limited testing ability and from results in threads I had read here, I ordered a new turn signal/mf switch (SW2443).

I didn't have much time before work today when it arrived, but I got the switch installed put the headlight switch back on. Switched it on, went to the front and noticed my headlights/parking/sidemarkers on, and no foglights. Ok I thought, at least I have headlights again, turned the headlight switch back off and realized the headlights were still on (nothing else). I had to pull the negative battery cable to get them off.

As for the wiring at the multifunction switch, the r/blk wires had a lot of corrosion at the terminal (similar to caked on battery acid) and the r/y wire was charred. I cleaned up using electrical contact cleaner, still not a new appearance but the green corrosion is all gone. I removed the wires from the m/f harness connector and discared it as it was badly burnt, and plugged them straight into the new m/f switch. If I remove the r/y wire the lights stay on. If I remove the grn/blk or the blue/o wire the lights come off. FTP, hi-beams, turn signals are not working (nothing lights up on the cluster either). Whatever is going on, it seems like the main beams being on is over-riding anything else from working. Could this possibly be as simple as my headlight switch itself being defunct?

What's next? (Didn't have time for voltmeter testing today)

 

[Darkwriter77]

Still sounds like the problem I was trying to figure out, myself - was getting either the headlights OR the parking lamps, never both. Spraying the contacts might not be enough to clean them - physically scraping them clean, or bypassing them completely, will likely be necessary. Worst-case scenario, you can either rig up your own plug with a bunch of female spade terminals, or buy a headlight switch pigtail from the junkyard and splice that in place of the other one.

Your problems might not ONLY be with the wiring, though. A new headlight switch is only like $15 at Autozone, last I checked. Not sure how much the multifunction switch is, but you could probably pick one up from a junkyard for a LOT cheaper than new.

 

[JustA5.0]

I used a brass brush and the cleaner, but I'll give it a try gently scraping the wire with a pick.

The multifunction switch is new.
Headlight harness connector is new, the old one was burnt, but none of the wires looked bad when I transferred them over. Also, I have a Ford service CD and the troubleshooting order it gave for the headlight switch, all passed on the voltmeter.
I do have a new pigtail for the multifunction side of the wiring that I have yet to do any splicing/soldering with, simply because soldering is not my speciality.
Headlight switch is original.

My guess is the headlight switch is no good, or it's something to do with the r/y wire at the multifunction end of things. I don't see how the headlights would stay on with the r/y wire disconnected from the mf switch.

*Edit* Something I wrote in my OP

Prior to this, obviously foglights weren't working, headlights, parking lamps, taillights and all that worked. When I begun taking things apart the previous owner had cut one of the brown wires from the headlight harness (6-pin) and spliced it with the light/blue black wire from the foglight harness *shrug*. I got rid of this mystery and soldered the brown wire back together by itself. I suck at soldering and this was a tricky location to solder, so including this info incase it makes a differance.

This brown wire on the headlight switch (#5 position I believe with the two brown wire split) is the only thing, I think I did poorly. Is this wire not properly grounding causing the headlights to remain on?

 

[jrichker]

Some help in the soldering area...

How to solder like a pro - Ford Fuel Injection How To Solder Like a Pro a must read for any automotive wiring job.

 

[Saleen0679]

I suspect the LB/BK wire splice was an uneducated attempt at having the fog lights on with the parking lights. Wired this way the fogs would have been on anytime the exterior lights were on and was the likely cause of charred wiring. The fog light fuse would also have been bypassed.

Verify that you haven't mixed up the wiring in the small rectangular connector at the MF switch. Top to bottom the colors should be:

R/Y
R/BK
LG/BK
DB/O

Somehow you're getting power to the high beam circuit (LG/BK) by way of the FTP circuit (DB/O via fuse #10). This would not be under the control of the headlight switch.

Check out the Headlight and Exterior light schematics in the EVTM section on the Ford CD.

 

[JustA5.0]

Some help in the soldering area...

How to solder like a pro - Ford Fuel Injection How To Solder Like a Pro a must read for any automotive wiring job.

Lol, I actually used those very directions for the soldering. However, the old brown wire did not want to 'twist' together with the new section of wire I added (where the PO had spliced the foglight wire into this). I basically srucnched the new & old together as best I could, wrapped some solder around it, and tried to solder between the windshield and steering wheel. You can't pull the solder joint apart, but it's a blob of a mess IMO .

Soldering on a bench I can do, but in the confines of the car I suck at it.

 

[JustA5.0]

I suspect the LB/BK wire splice was an uneducated attempt at having the fog lights on with the parking lights. Wired this way the fogs would have been on anytime the exterior lights were on and was the likely cause of charred wiring. The fog light fuse would also have been bypassed.

Verify that you haven't mixed up the wiring in the small rectangular connector at the MF switch. Top to bottom the colors should be:

R/Y
R/BK
LG/BK
DB/O

Somehow you're getting power to the high beam circuit (LG/BK) by way of the FTP circuit (DB/O via fuse #10). This would not be under the control of the headlight switch.

Check out the Headlight and Exterior light schematics in the EVTM section on the Ford CD.

Saleen, ok that's a bit of relief, the brown wires being for the parking light circuit, not ground. By foglight fuse, do you just mean fuse #15 was bypassed this way?

I will check the wiring order, and look deeper into the EVTM section.

Keep my fingers crossed

 

[Saleen0679]

Saleen, ok that's a bit of relief, the brown wires being for the parking light circuit, not ground. By foglight fuse, do you just mean fuse #15 was bypassed this way?

I will check the wiring order, and look deeper into the EVTM section.

Keep my fingers crossed

Yes. If the PO connected the LB/BK to the BR wire he would have had to sever the circuit after the fuse (#15) and before the fog light switch effectively connecting the fog light switch directly to the head light switch and bypassing the fuse. To keep the fuse in circuit the R/BK wire would have had to be connected to the BR wire. Still not the way to do it, but the fuse would have been in circuit.

 

[JustA5.0]

Update:
Saleen was right about the MF wiring, I had it installed bottom to top. Swapped that around and everything works again, EXCEPT the DAMN FOGLIGHTS!!! I'm back to square one, except probably $250 in the hole with the switch, wiring, bulbs, relays and crap.

Continuity tests performed using ohmmeter:
Headlight switch, passed as per Ford EVTM.
Foglight switch, passed as per Ford EVTM.
All my modified wiring in the dash, including the crappy splice job I did on one of the two brown wires, showed full continuity.
Relay has 12v coming from the fused battery.
There is continuity at my foglight harness to the battery terminals, continuity on the foglight end as well between itself.
Bulbs are brand new 55w, installed with a fresh towel (no smudges).

WTF, I really wish I had my money back and these things not working, but I can't so I NEED them to work.

I don't know what else to test, even though the foglight switch showed continuity can it still be bad?

 

[HISSIN50]

Update:
Saleen was right about the MF wiring, I had it installed bottom to top. Swapped that around and everything works again, EXCEPT the DAMN FOGLIGHTS!!! I'm back to square one, except probably $250 in the hole with the switch, wiring, bulbs, relays and crap.

Continuity tests performed using ohmmeter:
Headlight switch, passed as per Ford EVTM.
Foglight switch, passed as per Ford EVTM.
All my modified wiring in the dash, including the crappy splice job I did on one of the two brown wires, showed full continuity.
Relay has 12v coming from the fused battery.
There is continuity at my foglight harness to the battery terminals, continuity on the foglight end as well between itself.
Bulbs are brand new 55w, installed with a fresh towel (no smudges).

WTF, I really wish I had my money back and these things not working, but I can't so I NEED them to work.

I don't know what else to test, even though the foglight switch showed continuity can it still be bad?

Have you checked I/O voltage with a load on the fog light switch?

If I/O voltage at the switch is ok:
On the foglight relay, you have checked that there's fused battery 12 volts reaching the relay (terminal 30 or 87)?

Have you checked relay terminals 85 and 86 for power and ground (which is which does not matter on a cheap Bosch-style SPDT/SPST, so long as ground goes to to one terminal and 12 volts goes to the other)?

If you have those 3 covered, there should be power going towards the fog lights. Be sure the fog light grounding pathway is copacetic.

 

[seijirou]

Have you checked I/O voltage with a load on the fog light switch?

If I/O voltage at the switch is ok:
On the foglight relay, you have checked that there's fused battery 12 volts reaching the relay (terminal 30 or 87)?

Have you checked relay terminals 85 and 86 for power and ground (which is which does not matter on a cheap Bosch-style SPDT/SPST, so long as ground goes to to one terminal and 12 volts goes to the other)?

If you have those 3 covered, there should be power going towards the fog lights. Be sure the fog light grounding pathway is copacetic.

Hissin beat me to it.

Also beat me to the use of the word copacetic.

Next time Hissin!

 

[2BADSTANGS]

Sounds like a stupid question, but have you verified that the fogs themselves work? I just scanned over this thread, so if that has already been covered, forgive me.

 

[JustA5.0]

Conclusion:
I decided to get more technical and in depth by speaking to Hissin50 through PMs. He explained more tests to do and what the results would indicate.

In the end the T/O wire that runs out to the fogs was cut around the drivers framerail under that mass of wires . Easy solution, difficult to find.

For anyone who reads this thread having exterior lighting problems (mostly obvious unless you're an electrical noob like myself).
1. Do the GT foglight fix
2. Since the gauge pod and steering column trim is already removed, inspect the plastic harnesses for burn damage. Key wire being R/Y between the headlight and mf switch. If plastic is burnt, remove the wires and inspect them for corrosion/burnt and clean them up.
3. If you can, order a multifunction switch somewhere that will let you return it if unopened. If yours is faulty, you'll have one ready to swap. This would have saved me a couple of days waiting for one to come in.
4. If your fogs still aren't working check the relay for voltage and switching voltage. If voltage is coming in, but not switching over, do a continuity test on the headlight/fog switch itself (replace if necessary). If the relay is switching fine, immediately proceed to the harness at the foglight side and test here for voltage/resistance. This would have said me time troubleshooting, and falsely doubting that the relay was working.
5. Unfortunately, the GT foglight fix will probably not be all our cars need. I'm not sure how long ago that article was written, but with my Fox being 21 years old the wiring system is just going to become more brittle and damaged, until you fix it. Do some additional research beforehand, and make sure you budget more than a relay and wires.

Approximate cost...
$120 for the MF switch from RockAuto. I bought motorcraft, didn't bother with the aftermarket solutions.
$50 for the relay, fuseholder, wiring supplies (though I do have left over wire and connectors)
$25 for the plastic headlight harness and multifunction side harness shells.
$10 for new H3 bulbs (old ones looked newish however)
$205 may seem a lot, but I won't have wiring/plastic melting behind the dash anymore. Plus I learned how to troubleshoot wiring. As well, the fogs eliminate the blackhole DOT lighting gives off. I have euro H4s on another car of mine, and knew those German Hellas would be powerful little fogs.

 

[keithnra]

I suspect the LB/BK wire splice was an uneducated attempt at having the fog lights on with the parking lights. Wired this way the fogs would have been on anytime the exterior lights were on and was the likely cause of charred wiring. The fog light fuse would also have been bypassed.

Verify that you haven't mixed up the wiring in the small rectangular connector at the MF switch. Top to bottom the colors should be:

R/Y
R/BK
LG/BK
DB/O

man i needed this wiring diag
Somehow you're getting power to the high beam circuit (LG/BK) by way of the FTP circuit (DB/O via fuse #10). This would not be under the control of the headlight switch.

Check out the Headlight and Exterior light schematics in the EVTM section on the Ford CD.

i needed this