Hey guys, my headlights are giving me crap. They will work with the truck off, have no blinking, no flickering, nothing. But when you start the truck, the lights begin to flicker and then eventually go out, nowhere to be found again, until you shut the truck off and give it 5-10 minutes before they'll come back on.

What do I do?

 

Does gently moving the light switch do anything BEFORE they go out?

-Enjoy
fh : )_~

 

I haven't tried that. Honestly, most of the time when I try the headlights, they do nothing. My low beams haven't worked since I got the truck unless I have no idea how they work, and only my brights work very rarely (if that is what the blue headlight light on the dash means)

 

...

-Enjoy
fh : )_~

 

on the floor under the parking break is the dimmer switch. step on it and the low beams should switch on.

for the flashing then dying lights, you will need to replace the headlight switch in the dash, and most likely the electrical connector at the switch. both parts are usually stock items at respectable auto parts stores.
a good mod is to do headlight relays. this will cut power going through the switch to about 1/50th of what it is now and then the switch and connector will no longer burn up

here is a very good write up on how it works, and also how to do it. :
Daniel Stern Lighting Consultancy and Supply

 

Sorry Festus, I'm too young for these older cars!

 

I don't know when they changed over, but doesn't the 90 have the dimmer on the Turn Signal switch?

I didn't follow the Daniel Stern technique ...

I did it my own way, in/under the dash between switch and dimmer using one relay for headlights. I did split off my running lights using a second relay because I have lots of running lights between trailer and truck and wanted them on a different circuit.

The best time to do my technique is when doing the headlight switch and pigtail.

-Enjoy
fh : )_~

 

dimmer switch from floor to mutifunction stalk was first used on the 92 trucks. 91 still had the floor switch.

i did my own relay setup many many years ago too. i think it was in 1990.
but it is pretty much the same as that link. and his drawings are pretty good as to how to do it, so i refer people to it when asked because it is easier that trying to describe how to do it.

 

Donke, Tom

-Enjoy
fh : )_~