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73-87 Chevy _ GMC Trucks => Electrical => Topic started by: bicent truck on January 03, 2007, 04:56:00 AM

Title: NO BRAKE LIGHTS TURN SIGNALS
Post by: bicent truck on January 03, 2007, 04:56:00 AM

I took bed off for restoration of 76 C10 longbed, and recently needing truck on the road to get some welding done ( new exhaust), I can't seem to get the brakes or lights in general to work on rear of truck. I tied the lights and harness back onto frame temporarily, and screwed the ground to the frame, which I think it might be still a grounding problem. I have power back there with a test light. I did paint the frame with rustproofing after grinding and cleaning it, but sanded a small spot in frame where ground was fastened for good contact. Any suggestions? Not sure if it's directly related but my fuel gauge doesn't work properly all of a sudden after 30 years, is this tied directly into ground or lights or just a coincidence. Everything going the wrong way right now, instead of improvements I'm going backwards!  

Title: Re: NO BRAKE LIGHTS TURN SIGNALS
Post by: roundedline on January 03, 2007, 01:49:00 PM

How are the front turn signal lights?  Do they work?

Chris Lucas
www.73-87chevytrucks.com
www.captkaoscustoms.com
Project Su
Jimmy 2WD Project

Title: lights
Post by: bicent truck on January 03, 2007, 05:49:00 PM

front directional lights both work fine, nothing working in rear, they worked fine with bed on few months ago.

Title: Re: lights
Post by: roundedline on January 04, 2007, 12:00:00 PM

Is the rear harness grounded?

Chris Lucas
www.73-87chevytrucks.com
www.captkaoscustoms.com
Project Su
Jimmy 2WD Project

Title: ground
Post by: bicent truck on January 04, 2007, 05:33:00 PM

the ground wire off rear harness is bolt and nutted to frame. I sanded the hole it went in since I previously paintd frame with anti rust.

Title: Re: ground
Post by: VileZambonie on January 05, 2007, 03:37:00 PM

Is the rear harness plugged in?

Title: Brake lights
Post by: bicent truck on January 05, 2007, 05:17:00 PM

Rear harness is plugged in

Title: Re: Brake lights
Post by: VileZambonie on January 06, 2007, 08:39:00 AM

Title: running lights working
Post by: bicent truck on January 09, 2007, 05:54:00 PM

The parking lights are now working but still no blinkers or brake lights, i did re-do the ground by sanding through the anti rust coating on the frame, but that's only part of the problem it seems. Lights are working on front.

Title: Re: NO BRAKE LIGHTS TURN SIGNALS
Post by: CruzinHigh on January 14, 2007, 02:58:00 PM

Perfect timing for your post.  I just recently rebuilt my entire harness for the headlights, gas sender, and rear tailights.



This is the entire rear harness.  (One of those 4 pin weatherpack connectors was added by me for splicing in for a trailer connection)

The rear harness is only connected with a 4 pin weatherpack connector, bringing the 12v in for the 4 circuits.  No grounds in this connector.



Now, lets talk about the grounds.  That rear harness is loaded with factory splices.  Most are for the brown wire, and the other larged spliced circuit is for the grounds.  They are wrapped up in black duct tape inside the harness.  I bet that most of us would be horrified to see just how pathetic these connections are by now, after years of corroison and wear and tear has set in.  This is what the splices looked like in tailight gound circuit for my 86 K-10...




I would highly suggest you pull that rear harness and go through it.  My main ground was through a ring terminal bolted up to the bed under the LR tailight housing.

I added redundant grounds, back to the frame and into the harness, about 3 all total out back!  You can NEVER have too many gounds.

I also grounded the bed to the frame and jumped it to the filler neck with a 4 gauge cable.

Your fuel sender has a ground just running from the sender right to the frame.

It sure sounds like the factory ground to the frame is suspect.

Try jumping a cable from the bed to the frame, and then route a jumper from frame up to the battery (-).  That should cover all the bases.  If it still doesn't work, then your rear harness is in need of a look through.

Title: CruzinHigh
Post by: bicent truck on January 15, 2007, 05:01:00 AM

Thanks for all your time and help. I will get to that harness and fuel sender as soon as weather is permitting. Unfortunately, I don't have a garage here in NJ.This was a great post from you! Thanks again Rich