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73-87 Chevy _ GMC Trucks => Electrical => Topic started by: cramezl on November 06, 2013, 12:07:27 pm

Title: Need help diagnosing headlight problem.
Post by: cramezl on November 06, 2013, 12:07:27 pm
Tightening up loose starter bolts the other day. I managed to short out the starter wires on my exhaust. Now my headlights don't work. I have brakes and turns. No headlights, dash lights, and not sure about cargo lights.

I have a brand new headlight switch, all fuses under dash are good, and I have power to junction box on firewall in engine bay. Not really sure where to go from here.

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Title: Re: Need help diagnosing headlight problem.
Post by: bd on November 06, 2013, 01:09:19 pm
Check the two fusible links coming off the starter.
Title: Re: Need help diagnosing headlight problem.
Post by: cramezl on November 07, 2013, 09:25:59 pm
Found a wire off the starter solenoid that was burned through. Fixed that and now i have headlights again.

But, I don't have dash lights. And my floor light under dash stays on constantly, along with my dome light. The dome light is dim unless i turn the headlight knob all the way to the left, then it's bright.

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Title: Re: Need help diagnosing headlight problem.
Post by: cramezl on November 07, 2013, 09:26:45 pm
I didn't change any wiring other than fixing a connection that was previously there. Could my new headlight switch be faulty?

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Title: Re: Need help diagnosing headlight problem.
Post by: Captkaos on November 07, 2013, 09:34:13 pm
Is it a new switch?
Title: Re: Need help diagnosing headlight problem.
Post by: bd on November 07, 2013, 09:45:59 pm
Concerning the courtesy & dome lights, check the operation of the door jam switches mounted in the cab door frame between the hinges.  One may have been pushed out of adjustment.

To check the dash lights, read...  Diagnosing dash lights that don't work (http://forum.73-87chevytrucks.com/smforum/index.php?topic=26558.msg221363#msg221363)

To help with your diagnosis, refer to the appropriate year wiring manuals in our Technical Pages - here (http://forum.73-87chevytrucks.com/smforum/index.php?topic=11766.msg87585#msg87585) and here (http://forum.73-87chevytrucks.com/smforum/index.php?topic=25639.msg213706#msg213706).
Title: Re: Need help diagnosing headlight problem.
Post by: cramezl on November 08, 2013, 08:48:11 am
Is it a new switch?

Brand new. Broke the old one trying to fix my lights.

Thanks bd. I'll take a look

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Title: Re: Need help diagnosing headlight problem.
Post by: rich weyand on November 08, 2013, 08:48:33 am
Found a wire off the starter solenoid that was burned through. Fixed that and now i have headlights again.

But, I don't have dash lights. And my floor light under dash stays on constantly, along with my dome light. The dome light is dim unless i turn the headlight knob all the way to the left, then it's bright.

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That sounds like a ground problem.  There should be a ground strap from the P side rear of the engine head to the firewall and one from the D side front of the head to the frame rail.  Check for those, and check that they are clean and tight.
Title: Re: Need help diagnosing headlight problem.
Post by: cramezl on November 09, 2013, 08:46:49 pm
Concerning the courtesy & dome lights, check the operation of the door jam switches mounted in the cab door frame between the hinges.  One may have been pushed out of adjustment.

To check the dash lights, read...  Diagnosing dash lights that don't work (http://forum.73-87chevytrucks.com/smforum/index.php?topic=26558.msg221363#msg221363)

To help with your diagnosis, refer to the appropriate year wiring manuals in our Technical Pages - here (http://forum.73-87chevytrucks.com/smforum/index.php?topic=11766.msg87585#msg87585) and here (http://forum.73-87chevytrucks.com/smforum/index.php?topic=25639.msg213706#msg213706).

Big thanks to bd for posting that. The first link solved my problem. Bad courtesy/tl fuse was the problem. And I checked all the fuses at the beginning of this ordeal...
Title: Re: Need help diagnosing headlight problem.
Post by: bd on November 09, 2013, 09:37:57 pm
Glad you found it useful.   ;)