1994 Headlight Problem...

[freeloader]

First post....

 

I just purchased a 1994 GMC Sierra 1500 PU for $500. The body is in good condition and mechanically it's in great condition. However, the electrical system is not so good. The horn doesn't work at all, the headlights go out when you turn on the low beams (but the high beams work), the reverse lights don't work and the cargo lights and courtesy lights don't work.

 

I've checked all the fuses for the above systems with a multimeter and they're in working order. Is it possible that a fuseable link has died or is this just a case of individual failure in the separate systems? My main concern is the headlights right now. Switch or headlights? Any help would be greatly appreciated.

[Zembonez]

Those trucks really weren't known for electrical problems... certainly not in bunches like you have. I'd check all grounds first. It sounds like somebody has either modified or unsuccessfully "repaired" something in the wiring. Pretty hard to diagnose by remote control but maybe some more people will chime in here.

 

Silly question but... have you ruled out bad bulbs? I know it's obvious but worth checking all of the bulbs before you start chasing problems that might not be there. Headlights should have high and low beam relays underhood.

 

500 bucks sounds like a good deal. I'd invest in a Mitchell manual for the truck. It could save a lot of headaches.

 

Welcome to the ZOO!

[freeloader]

Those trucks really weren't known for electrical problems... certainly not in bunches like you have. I'd check all grounds first. It sounds like somebody has either modified or unsuccessfully "repaired" something in the wiring. Pretty hard to diagnose by remote control but maybe some more people will chime in here.

 

Silly question but... have you ruled out bad bulbs? I know it's obvious but worth checking all of the bulbs before you start chasing problems that might not be there. Headlights should have high and low beam relays underhood.

 

500 bucks sounds like a good deal. I'd invest in a Mitchell manual for the truck. It could save a lot of headaches.

 

Welcome to the ZOO!

 

I'm going to check all the bulbs tomorrow. I just did not think there could be so many bulbs blown at once. I'll let you know though.

[chevylobo]

reverse lights are easyest the circuit boards are prob shot that the bulbs plug into . i had the problem on my 88 was likea 20 doller fix from advanced auto

[freeloader]

Those trucks really weren't known for electrical problems... certainly not in bunches like you have. I'd check all grounds first. It sounds like somebody has either modified or unsuccessfully "repaired" something in the wiring. Pretty hard to diagnose by remote control but maybe some more people will chime in here.

 

Silly question but... have you ruled out bad bulbs? I know it's obvious but worth checking all of the bulbs before you start chasing problems that might not be there. Headlights should have high and low beam relays underhood.

 

500 bucks sounds like a good deal. I'd invest in a Mitchell manual for the truck. It could save a lot of headaches.

 

Welcome to the ZOO!

 

Most of the problems turned out to be bulbs. I'm still trying to figure out the reverse lights though. I'm getting power back to the lights (at the plug connection), but still nothing. I'm going to pull the circuit boards and check them as chevylobo suggested.

[Mike G]

I'm still trying to figure out the reverse lights though. I'm getting power back to the lights (at the plug connection), but still nothing. I'm going to pull the circuit boards and check them as chevylobo suggested.

 

Sounds like a ground at the bulb/socket or perhaps the wrong bulb if you are getting heat at the bulb contact point.

--Mike