New 71 C10 Wiring Issues

[the hippie mechanic]

Hey all, I have some peculiar problems with my lights. I'm not too good with wiring so any help is much appreciated. I recently picked up a green 71 C10 that needed a new headlight, front turn signal, and parking lights. More info and pictures on that story in the link. The passenger's side headlight was dim so I cleaned up the contacts, got a new turn signal and some parking lights and plugged it all in. Before cleaning the contacts I would sometimes have a hi beam on the passenger's side, sometimes not. After cleaning the contacts on the passenger side neither driver's or passenger head light worked at all, hi or low.

In addition to that when the headlight switch is pulled out the entire left side turn signals won't work. The right signals will blink when the headlights are on and the driver's side works when the headlights are off but no driver's side signals when the headlights are on. The lights behind the gauges that come on when the headlights are on only come on sometimes but the hi beam indicator works fine so I'm wondering if it could be something behind the dash. I tried tracing the wiring diagram that's posted on here but it's pretty confusing. Other than that the brake lights, reverse lights, horn, and ignition work like a charm. Any help is much appreciated.

Pics of the truck: http://67-72chevytrucks.com/vboard/s...d.php?t=668643

[LockDoc]

.. to the board.

Sounds like grounding problems to me. Read this thread:

http://67-72chevytrucks.com/vboard/s....php?p=4200642

Be sure and read the whole thing.

Bad grounds or no grounds cause all kinds of strange problems....

LockDoc

[LockDoc]

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This was posted by GMCPaul in another thread. Make sure you have them all.

""For your motor you should have the ground wire from battery connected to the passenger side front of cylinder head, then at rear of both V-8 valve covers going from last bottom rear bolt on each valve cover should be a ground strap running from these bolts on both sides attached to the cab firewall, on passenger side front inner fender lower edge where it meets frame as it curves down should be another ground strap running from inner fender to frame, you should have a 4th ground strap running from frame to passenger side front cab support, and a 5th strap from rear bed cross-sill to frame, without all the proper grounding straps you can have a ton of odd electrical problems from some lights working intermittently, to poor charging, electrical parts failure, etc....

We carry the 5pc electrical ground strap sets with hardware to install on the following page of our web site if interested,
http://www.gmcpauls.com/Electrical.htm
GMCPaul ""

I also run a ground from the front of the frame to the core support on all of my trucks..

LockDoc

[the hippie mechanic]

Thanks LockDoc, I'll read through that. I'm glad you threw in that quote from GMCPaul, it reminded me to check how well my alternator is working. Hopefully going around and making sure the grounds are solid clears it up. Thanks for your advice!