88 GT CONV

Long story short: Driving 8 hour trip in the 92 5.0, both headlights and foglights begin to turn off and back on repeatedly (will turn off for roughly 3-5 seconds at a time). Now with that in mind, I think of a bad ground, or some sort of open/short before the load. The thing is, during the "flickering", if I turn the foglight switch off, the problem goes away. I have no wiring diagrams, but I assume that headlight/foglights in any vehicle are wired in parallel, right? That SHOULD mean that if one stops working, the others should remain lit... Anyone have this happen before? Thanks in advance...

mjr46

there was a inherient problem with the mustangs and the fog light wiring in that the circuit actually wasn't capable of carrying the current load and would short out the wiring and often affect the headlight circuit in the process because of the link between the two.......check the switch and the wiring from it to the fuse box for any melted/damaged wires and all the connections into the headlight switch for any overheated pins

cleanfitty

You overheated the headlight switch... running the foglights for a long time draws alot of juice and it overheats the switch. There are ways around it.

If any damage was done, the electrical connector that plugs in the back of the switch, gets crusty, but can also damage the multifunction switch.

cleanfitty

AHHHH!
you beat me to it

mjr46

AS fast as fast can be you'll never catch me!!!!!!!he he he!!!!!

88 GT CONV

OK thanks guys it makes sense. I'll check in the morning for the switch. Is there anything I can do while repairing this to prevent it from happening again? I can't stand the way it looks to run the headlights w/out foglights! Just so ya know, after I let the foglights rest for a couple minutes, I can turn them on and all works fine for quite some time. Still could be the switch?

mjr46

probably...you can rewire the fog lights and run new wires and use a seperate relay to run the fog lights and use the switch to control the ground side of the relay coil that pulls the windings in to activate the switch

88 GT CONV

So wire the switch between ground and 86?

mjr46

30 and 87 are your load carrying circuits.......so B+ to one terminal30 and the other side 87to the B+ for the fog lights........and 85 or 86 whichever you perfer can go to a switched 12v power source so the lights will only work with the key in the on position...and if you use 86 for switch 12v then use 85 to go to the switch and and the other side of the switch pin wire to ground so in reality the switch will control the ground side of the relay engagement so that way the switch will not carry a current load and overheat

88 GT CONV

Thanks alot man, glad you know what your talking about here, not too many people like electricity!