headlight problems...

[67cst]

hey guys ive been driving the 71 gmc for probably 6 months no and the inside headlights have never worked, the outside 2 work fine and when i flip to high beam they just get brighter, and the insides dont come on, all the wiring looks fine, maybe the 2 inside are just burnt out but could it possibly be something else?

[WRMZ71]

sounds like you need to get a multimeter or a test light and see if you got power going to your lights. If you don't have any power there, a major culprit is always the dimmer switch inside. Either they go bad or the wires get cruddy from the years of mud and water getting on em. If you do got power check your groundwire for the headlights. I don't know about GMC but on chevy's it's on the ds radiator support right next to the voltage regulator.

[cdowns]

easy way to check is get a nuw bulb and try it out

[67cst]

wrm- i was just going to check it out with my tester light, thanks for the heads up guys

[jef5150]

if im not mistaken the 2 inside lights are "high" beam only,why couldnt you put the connector from the "outside lights" on the inside light s on "high" beam (temporalily)to see if the bulbs are good or not? just a thought........jeff

[Longhorn Man]

The dimmer switch would not be the cause, if the outer bulbs switch to high beam, then it is doing its job.
Either some one has messed with the wires, or installed a chevy harness, or the bulbs are dead.