Headlights Driving me NUTS!!

SEE http://www.corral.net/tech/maintenance/foglights.html to fix the problem. The stock wiring isn't up to the job and is overheating. The headlight switch & turn/multifunction switch are affected by Ford's wiring problem. Sometimes it overheats so badly that the plastic shells of the wiring connectors start to melt.

hey jrichker was this ever recalled by ford?
i have delt with this in my 1987 lx
and now i have no head lights/highbeams
in my 1988 gt (passing beam is still functional though)
does anyone else find it strange that the same switch would be used in all
1987-1993 mustangs when they are clearly defective?
i mean look how many threads are posted about this topic.
didnt this start any damn fires back in 1987?
i mean what the hell !

The switch was fine till they added fogs onto the circuit. The switch has a thermoswitch integrated into it, which is why the lights go off and come back on sometimes (like an overheating hair dryer). It does seem to be a good bit rarer in LX's (no fogs).

Grey fox, the wire from the headlight switch to the MF switch (red/yellow IIRC) can burn or back out of the connector on either end. When this happens, you lose lows and highs via the headlight switch (parking lights still work since they dont go through that wire or the MF switch). And flash-to-pass still works since it does not source the red/yellow headlight switch wire for power. In my case, the red/yellow wire had backed out of the MF switch's connector ever so slightly. Fixed it up and I was good to go.

It seems to me that the switch was a TSB item perhaps, but not a recall AFAIK.

hey im a little lost whats the mf switch?
this is what i did to get the lights on.

i spliced into the red/yellow wire and ran a new lead to the engine bay, then i connected it to the red/black wire on the headlights.
i have a feeling that your gonna say that that is a terrible idea.
is the current regulated somewhere between the headlight switch and the lights?
do the headlights create a significant draw on the new wire i ran?/?
it seems ok but its making me nervous not knowing how this crap works
i dont understand wire diagrams

the new wire that i ran is some of that good quality (14 awg 600w) or whatever it is. its like the stuff thats in the car but stiffer.
im gonna burn my car down aint i ???

GREYFOX4INCH said:

hey jrichker was this ever recalled by ford?

Click to expand...

no,this was never a recall from Ford,at least not in the 10 years I was there,although i did replace a lot of them.

the M/F switch is the turn signal stalk,but since it does more then one thing its a multi function switch.

OK well that answers that,
as for my quick fix, is it safe???????
(btw, the two screws up by the windshield are going to die!! i hate them)

GREYFOX4INCH said:

hey im a little lost whats the mf switch?
this is what i did to get the lights on.

i spliced into the red/yellow wire and ran a new lead to the engine bay, then i connected it to the red/black wire on the headlights.
i have a feeling that your gonna say that that is a terrible idea.
is the current regulated somewhere between the headlight switch and the lights?
do the headlights create a significant draw on the new wire i ran?/?
it seems ok but its making me nervous not knowing how this crap works
i dont understand wire diagrams

the new wire that i ran is some of that good quality (14 awg 600w) or whatever it is. its like the stuff thats in the car but stiffer.
im gonna burn my car down aint i ???

Click to expand...

How you did it: not bad. A relay would be the way to do it better IMHO. When mine went, I did not have time to find the issue so I rewired the lows and highs on separate switches (rocker switches) for a little bit, but I did use relays to eliminate melting switches, etc. You really just bypassed the bad junction (at the MF switch). You probably lost your ability to flip the brights on, as well. But otherwise, the same amount of power is going through the headlight switch, etc.

Sorry, the MF switch = the Multi-function switch, which equals your turn signal switch. The MF switch is the Y in the road if you will - the headlight switch's power goes there and then when you flip the turn signal switch (for brights), the MF switch is what toggles you from lows to highs.

Accessing the MF switch wiring connector takes about 5 mins. I cant recall, but I think the switch is retained with small Torx screws. But I dont think I had to remove those to see my wire which had backed out.

Simple math for circuits: Volts * amps = watts.

Here is a link to what gauge to use when. When I am in doubt, I go big. Bigger gauge (smaller number) takes up more room but has no real downside (overkill does not hurt in this case).

14 AWG should be alright for the work you did.

Good luck with getting it fixed up back to spec (if you choose to do so).

hey thanks, i feel better now. i will leave it how it is and do somemore exploration to see if i can fix it how it should be. but i might just do seperate toggle switches like you did and leave it that way. the thing is, i still dont understand what is happening when the high beams are put on. i mean i know they are brighter but what is happening to make them brighter? i have aftermarket headlights, they are a projector style or somthing. insinde headlight assembly there is the main bulb and then off to the side there is a smaller bulb. (two bulbs both inside the center headlight piece [yes the square one] )

maybe ill just hang railroad lanterns in front of the car and remove the headlights all together. hey im learning

so i guess what im saying is how do i wire high beams to a toggle switch?????

GREYFOX4INCH said:

hey thanks, i feel better now. i will leave it how it is and do somemore exploration to see if i can fix it how it should be. but i might just do seperate toggle switches like you did and leave it that way. the thing is, i still dont understand what is happening when the high beams are put on. i mean i know they are brighter but what is happening to make them brighter? i have aftermarket headlights, they are a projector style or somthing. insinde headlight assembly there is the main bulb and then off to the side there is a smaller bulb. (two bulbs both inside the center headlight piece [yes the square one] )

maybe ill just hang railroad lanterns in front of the car and remove the headlights all together. hey im learning

so i guess what im saying is how do i wire high beams to a toggle switch?????

Click to expand...

I cant help much with the aftermarket projector style lights you have. On a stock headlight, the bulb has two elements (per bulb). When the brights are selected, the low beam goes out and the high beam comes on (as opposed to flash-to-pass, which illuminates both low and high beams IIRC). I have no clue how the projectors work though............

On the stock set-up, the wire for the brights can be found at the MF switch. I actually found it in the engine harness (the low beam wires, high beam wires and fog light wiring is all in the driver side engine harness). I installed relays on lows, highs and fogs, so that made sense to tap into the wires there. For you, I would find the brights-wire at the MF switch and use your toggle switch there.
I will note that the fix for me took a bit less time than the work to rewire switches and whatnot. I had incorrectly assumed that my MF switch failed and installed the switches rather than buy a new switch (another example of how getting in there and doing proper diagnostics can save time).

I would also caution against using lows and highs as the same time for very long. It is a large electrical drain (around 200 watts, ergo 17 amps or so) and the heat from both elements might get hot for the plastic housing (if you have them - again, I dont know snot about projectors). I once considered rewiring my brights to keep the lows on too, and these were concerns of mine.

If you do railroad lanterns, be sure they are USRR and DOT approved. I do dig how some of the projectors look.

Good luck.

VERY HELPFUL thank you!!!

the style of head light was already on the car when i got it but they do help create a very clean look with the shiney paint and the chrome rims, it all works on this car.

thanks again.