Headlight switch problem. Need help

[1985GMC]

85 gmc vin m

New headlight switch and plug. Only headlights work. If I take off the switch and run a jumper wire from battery wire in plug to anything other part of the plug the lights will go on. Why won't the switch carry the power? It's the second new one I got.
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[1985GMC]

bump

[hyatt]

check your fuzes all lights except headlights are fuzed

[1985GMC]

Fuses are fine. Everything is mint. I hate this dumb wiring crap. I don't understand why the switch won't transfer power.
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[motornut]

I believe the orange can feed the cig lighter too and the lights but not the headlights
make sure the male pins of the plug havn't push out of the holder
and the plug has seated firmly

[motornut]

Originally Posted by motornut

I believe the orange can feed the cig lighter too and the lights but not the headlights
make sure the male pins of the plug havn't push out of the holder
and the plug has seated firmly

orange and red should have power
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[Shyguy]

I had the same problem on my '67 and after a bunch of trouble shooting found out the problem was the turn-siganl switch in the column.

Like you I replaced the head-light switch as part of trying to figure out what was wrong.

I replaced it and now everything works. I am not sure about '73 and newer trucks if this will help.

[1985GMC]

Hmm we'll that's interesting. I just changed my turn signal switch and still no difference. Like I said if I run a jumper wire all the lights work. I feel like the advanced auto headlight switch is junk(even though its the second one I tried)
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[1985GMC]

Bump
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[Rich84]

Yes..The switch probably is junk..Maybe. And I agree with you that electrical problems are a pain in the butt. There must be a way to test the switch with a multimeter??

Good Luck.

[Rich84]

I bet it's in that turn signal switch... There is a lot going on in there. Maybe something with the high beam low beam switch.?

[silvereagle07]

Check to see if you have power at the headlamp on either side on circuit 11 (lt green) or 12 (tan) with the headlamp switch on. If you have power check the 151 (black) circuit for resistance to ground. It should be 5ohms or less. I usually prefer .5 ohms on a multimeter. As for the dimmer switch. The power feed comes on circuit 10 (yellow) to the dimmer switch. Remove the switch test and test continuity from circuit 10 to 11. Then test 10 to 12. If you show continuity the switch is good.

[1985GMC]

Thanks for the input everyone but I think we are steering off track. My headlights are the only thing that works with the switch. Turn signal switch is brand new and my blinkers and brakes work fine. It's my parking ad interior lights that won't work with the switch. Now as far a multimeter goes. Only the headlights is getting power when switch is connected. Like I said I can make all the lights work if I take the switch off and use a jumper wire. The switch must be bad but I would hate to buy a third one and have no difference.
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[85sierraclassic]

Isn't there more than one wire feeding the switch that should have power?

had this issue in a cutlass but never figured it out just jumped it because it was a beater.
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[1985GMC]

If this helps. Switch worked then I tied in a new headlight switch plug and all this started happening. I don't understand though.

Fuses are good
Bulbs are good
Lights work with jumper wire
New turn signal switch
New headlight switch
New headlight switch plug.
Proper voltage at correct wires.

Seems to me still that some how advanced autos switch doesnt work. I have had a Bulb socket from them not work at all either. I'm going to get a new switch from somewhere else. I don't know what else to do
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[Rich84]

Try hitting the boneyard...I was in Southington last week and there was 1/2 dozen squares there..I'd give you one to try but I just checked the shed and I don't have one.

[motornut]

hmm looking at this "typical exterior lighting" pic
seems both orange should have power
how do you mean tied in?
if touching should have power

[1985GMC]

LIGHTS WORK!

I found out that the two orange wires was the issue. Only one of the orange wires has 12v so I took the other one out and now everything works. The wire with no 12v was shorting the other 12v wire out.
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[motornut]

[QUOTE=1985GMC;6164912]LIGHTS WORK!

cool!

[melks]

I just recently replaced mine on my 84, everything was working except for the 4 headlights. Fuses were fine so I tried another original switch as well as another set of lights-to no avail. Had my mechanic take a look at it and he ended up using my original switch to get things working. No modifications or altering of wiring-he said he couldn't even tell me what he did to make it work, just plug and play. So I have come to a conclusion that these light switches have a mind of their own sometimes lol.

[melks]

replaced my alternator recently and I haven't had a problem since...I'm thinking that was the problem.