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91 GT: Headlights won't work

  • Thread starter Thread starter TheUser
  • Start date Start date Apr 16, 2005
T

TheUser

Active Member
Jul 25, 2003
1,859
1
36
Springfield, MO
Apr 16, 2005
#1
  • Apr 16, 2005
  • #1
I'm not real sure where to start. My headlights on my GT worked last fall when I put it up, but now that I'm about to drive it this spring, they don't work. I swapped headlight switches w/ my LX and that's not it. It's not the bulbs. Both marker/parking lights work as well as the tail lights, but the headlights don't work. Something tells me it's the headlight relay, but where is that located?

I got Tmoss' retrofit wiring diagram thing and my manual, but I'm not sure where to start. I was just wondering if there are any tricks or something I could do besides to start tearing things apart. I was gonna check the resistance of the wire from the dimmer switch (red/black) to the headlight connector, but I'm not sure how to get at the dimmer switch and don't want to do more than I have to. I guess I could do the retrofit while I'm at it, but I'm not the best at wiring.

Any ideas?
 

HISSIN50

"How long does it take to get help in here?
15 Year Member
Nov 29, 1999
31,179
33
129
Apr 16, 2005
#2
  • Apr 16, 2005
  • #2
Hello James. i would pull the column covers off and get access to the MF switch - that is like the fork in the road for headlight wiring. if you have 12 volts out of the headlight switch (for headlights) to the MF switch, the headlight switch should be alright.

i have had the headlight wire back out of the MF switch connector before (it is a decent size - like 12 or 10 AWG - wire (red/yellow perhaps). if that backs out, no highs or lows (except flash-to-pass).

but at the MF switch you can probe wires to see what is missing (obviously the MF switch is where the power from the headlight switch is div'ied up for lows or highs).

there is not a stock headlight relay that i am aware of. i chose to install relays on my lows, highs and fogs, which i would not have done if there was an oem relay. the stock headlight switch has a thermal switch (like your hairdryer) but that is about it (when factory lighting starts to flicker or comes back to life after being off for a bit, it is usually because the internal overheat switch reset, like a CB).

the fog light relay is a great idea, but if you dont have the fogs on right now, and you dont see signs of collateral damage from previous fog light use (i.e. burned wiring or connectors), i would assume they are not the cause of the issues right now.

i put my lighting relays under the hood, as i had 3 and i live in a nice climate (where weather affecting the relays was not a real issue). you can put relays inside the cockpit, per many write ups, if you want to. personal choice.

and dont fear the wiring - it is very simple if you want to upgrade.

good luck bud.
 
T

TheUser

Active Member
Jul 25, 2003
1,859
1
36
Springfield, MO
Apr 16, 2005
#3
  • Apr 16, 2005
  • #3
Thanks HISSIN. You definately helped me out on this one I pulled the column cover off and the bottom part of the dash there that covers that area and then the metal part and pushed on the wires and they work now

The bad part is, I had my head light bulb out and left the plastic covering on there and went to wash the car....the plastic covering is gone...I heard it bouce off the pavement lol, so now I guess I'll have to tape the bulb up there
 

HISSIN50

"How long does it take to get help in here?
15 Year Member
Nov 29, 1999
31,179
33
129
Apr 16, 2005
#4
  • Apr 16, 2005
  • #4
glad to hear it worked for you. when i first joined, i had a similar problem. i think my first thread was about the same deal and a guy named Fia Cobra helped me out - i still remember that!

on the headlight - was it the circular retainer with the little lock tabs (sets in, turn it and it locks the headlight bulb in place in the housing)?

i know you can get them at LRS for like 3 bucks (just placed an order and i think i saw the price right) or i *think* i have seen them at parts stores. i bet half the fords of that vintage use the same retainers (of those that had big headlights with H4's, which were many) - maybe a J/Y can hook ya up.

in any case, not a biggie. you could probably very lightly silicone the bulb in there (like the 4th gen camaro guys do when they swap bulbs but not housings) till you get a new retainer.

good luck James.
 
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