Headlight fuse/relay?

[81GMCSierra1500]

Where is my headlight fuse, I am suspect there is something wrong with the fuse... I have the issue where when my headlights are on regular "running lights," everything BUT the top two headlights are on, and when I turn my high beams on, only the top two headlights turn on, and when they dom they only turn to the regular "running" type setting... None of the local shops know what is going on, so I have ZERO help, and it's really, really beginning to frustrate me... also where is the fuse for the gauge lighting, I haven't got gauge lighting either... Errrrgh

[81GMCSierra1500]

I.E: High beam/low beam fuses, and gauge lighting fuses... Something is blown in there, I've checked every fuse I could get access to (some where obstructed by plugs I couldn't get out -_-) and nothing is blown...

[Just call me Sean]

Sounds like a switch problem. Headlight or dimmer or both. Instrument panel feed is through the parking light circuit, they work when the parking lights are on, but with a separate fuse. The fuses for the three circuits are under the dash in the panel.

Another possibility is a loose dashboard ground. Best way to describe it is everything goes all screwy, especially the lighting. High beam indicator on when low beams are on, very faint gauge lighting. Almost sounds like you may be describing that.

[81GMCSierra1500]

Originally Posted by Just call me Sean

Sounds like a switch problem. Headlight or dimmer or both. Instrument panel feed is through the parking light circuit, they work when the parking lights are on, but with a separate fuse. The fuses for the three circuits are under the dash in the panel.

Another possibility is a loose dashboard ground. Best way to describe it is everything goes all screwy, especially the lighting. High beam indicator on when low beams are on, very faint gauge lighting. Almost sounds like you may be describing that.

And how would I go about fixing a lose dashboard ground, that's almost exactly the scenario that I'm experiencing... with the headlights not working right, no gauge lighting or under dash lighting, turn signal speed increases and decreases etc...

[Just call me Sean]

You just have to find the main ground and make sure it is tight and making a good connection. I think it's under the dash left of the column. You'll see several wires bolted to the metal part of the dash.

[463]

here's one http://67-72chevytrucks.com/vboard/s...d.php?t=372788

[81GMCSierra1500]

Originally Posted by Just call me Sean

You just have to find the main ground and make sure it is tight and making a good connection. I think it's under the dash left of the column. You'll see several wires bolted to the metal part of the dash.

Will check that tomorrow when I've got some light to see That'll probably be the culprit... I will inform you of any developments. Thanks a mill, Sean

[463]

Are you sure that the low beam light bulbs are working?

[81GMCSierra1500]

Originally Posted by 463

Are you sure that the low beam light bulbs are working?

They have to be, as when I hit the headlights (pull the knob), none are on, but everything else is, tail-lights, park lights, side marker lights and my "limo lights" but the regular low beams are off (entire front clip, minus park lights, is dead) then when I press the high beam button on the floor, only the regular low beams come on, with all other lighting remaining the same. (I have the quad headlight version). I hope this makes sense... It's incredibly frustrating, as nobody really knows what's wrong...

[81GMCSierra1500]

Originally Posted by 463

Are you sure that the low beam light bulbs are working?

Also, both of the top headlamps (running & high, as opposed to just high on the lower two) were replaced just recently with brand new ones, so the chances of them being the culprit theoretically should be fairly low...

[463]

Bad dimmer switch or the plug on the switch, broken ground wire on the head light ground under the hood?

[81GMCSierra1500]

Originally Posted by 463

Bad dimmer switch or the plug on the switch, broken ground wire on the head light ground under the hood?

Can't be a bad dimmer, it's brand new, and the ground wire looks okay, but I'll check...

[463]

test the head light plug to make sure it has 12 volts and check to see that there is a good ground to the bulb.

[81GMCSierra1500]

I just looked over the entire front clip of the truck, and the only thing that really looks "bad" is the dround wire that runs from the negative terminal of the battery, to a bolt on the radiator support, then to the from via a second wire, the ground that runs to the rad-support is barely there, could that be the problem? I know it doesn't even directly connect to the lights, but could it contribute?

[81GMCSierra1500]

And I also don't have a voltage tester, nor the funds to get my hands on one...

[463]

That is more than likely what happen. the rad support must have a ground in place to complete the electrical circuit

[463]

You can fab up a simple tester with a 12 volt light and a pig tail for testing.
Like this http://www.rockauto.com/catalog/more...319&cc=1143144

[81GMCSierra1500]

Originally Posted by 463

That is more than likely what happen. the rad support must have a ground in place to complete the electrical circuit

I must try this then, last I remember now, the doofus' I had it in the shop with, messed around with it, and ever since, it's given nothing but electrical issues... Good investingation, and I will keep you updated!

[463]

them " doofus' " lol.
On a side note in may of 2013 I made my first trip out to the island. we went to Port Hardy and back down to Victoria , Very nice place.

[81GMCSierra1500]

Originally Posted by 463

them " doofus' " lol.
On a side note in may of 2013 I made my first trip out to the island. we went to Port Hardy and back down to Victoria , Very nice place.

There's no place like the Island and there tends to be a lot in the Comox Valley... The whole time I was in and out of the shop, nobody there noticed that my carburetor was barely bolted to the motor... -_- so I have to find a new, better shop...