passenger side tail light - The 1947 - Present Chevrolet & GMC Truck Message Board Network

rick0312 · 10-09-2011, 06:22 PM

passenger side taillight and side marker not working. all other lights are fine. tried to isolate the hot wire going to that light and got a reading of 2.0 volts. also license plate light is out too. any suggestions?...........thanks

68gmsee · 10-09-2011, 06:38 PM

First... If you haven't done it already, go and purchase a few ground straps at the local auto parts store.

Here's the reason why. These lights use the bed/frame ground to work and after 40+ years the bolts are rusty and covered in road grime so that you don't get a good ground back to battery negative post.

Here's what I did to completely ground the whole truck.

-Bought new battery cables and made sure the neg one made a good connection to the engine.
-Put a strap from the back of the bed to the frame.
-Another strap from back of the cab to the frame.
-Made sure I had a good ground to the cab from the back of the engine.
-Placed another strap from radiator support to the battery neg post.

All my light gremlins went away and my charging gauge started working again.

bmfm64 · 10-09-2011, 08:04 PM

I'd definitely check grounds but it sounds like the wire going to the taillight on that side has a break. Usually if a ground is bad the whole back end quits working or functions erratically. I would start at the connection under the rear of the truck where the rear harness connects to the main harness, figure out which one is the park light wire (brown I think) and follow it until you find the break. If the drivers side works there is a break because the same wire feeds all the park lights and plate light.

68Gold/white · 10-09-2011, 08:46 PM

I've had similar problems, trying to remember what all was wrong.....

Check the connection at the socket area. seems like that was a problem w/ mine. If the pass side has a problem, check the other side, while you are having all this fun...

You can't have too many grounds, anywhere on any vehicle.

If you've never completely looked over your wiring, as bmfm stated, you need to look it over, it's not too difficult, there's a harness that's on the frame rail.

big_al_71 · 10-09-2011, 08:58 PM

This happened to ny truck last week after we finished installing my autometer gauges my truck has all the wires brand new and i mean the complete truck extra grounds and all the problem was in the dash harness there is a plug that connects to another harness that plug was slightly loose we reconnected it and the rigjt side lamps started working we tie wrapped it so it wont come apart again. Check that plug is right behind the speedo head just above the fuse box.
Posted via Mobile Device

rick0312 · 10-09-2011, 11:29 PM

line had a break in it. luckily it was close to the light. now I hope i remember how to put everything back. PO hack in a trailer harness so that is making things a bit tricky.

68gmsee · 10-09-2011, 11:33 PM

Glad you found the problem. I forgot to add on my post that the grounding were a first step before looking for other gremlins.

I chased a problem for days until I found it was bad grounding that were making my lights act up. They would work sometimes and then they would not work. Really made no sense at the time.

stsalvage · 10-10-2011, 01:37 PM

Quote:

Originally Posted by rick0312

line had a break in it. luckily it was close to the light. now I hope i remember how to put everything back. PO hack in a trailer harness so that is making things a bit tricky.

a new repop harness back there will run you from 40.00 to 85.00 from M&H wire harness WWW.truckandcarchop.com

rick0312 · 10-10-2011, 10:43 PM

hooked light back up but must ahve done something wrong. all lights come on, but when I hit the brake the passengerside brake light goes out!!!. what did I do wrong?.thanks

MacGyver72 · 10-10-2011, 10:49 PM

That DEFINITELY sounds like a ground problem to me. It also can be related to your trailer light hookup. The others are right. Ground everything you can.

rick0312 · 10-11-2011, 12:56 AM

all is working fine now. i removed the trailer harness and cleaned up the grounds. thanks for all the input. you guys are the best!

MacGyver72 · 10-11-2011, 12:58 AM

Excellent! Glad you got it fixed.

10-09-2011, 06:22 PM	#1
rick0312 Registered User Join Date: Jan 2006 Location: Warrington, PA Posts: 403	passenger side tail light passenger side taillight and side marker not working. all other lights are fine. tried to isolate the hot wire going to that light and got a reading of 2.0 volts. also license plate light is out too. any suggestions?...........thanks __________________ 69 C10 LWB GM 350 crate motor, 3.73 rearend

10-09-2011, 06:38 PM	#2
68gmsee Active Member Join Date: Jul 2007 Location: Centrally located between Houston, Austin and Waco. BCS area. Posts: 7,947	Re: passenger side tail light First... If you haven't done it already, go and purchase a few ground straps at the local auto parts store. Here's the reason why. These lights use the bed/frame ground to work and after 40+ years the bolts are rusty and covered in road grime so that you don't get a good ground back to battery negative post. Here's what I did to completely ground the whole truck. -Bought new battery cables and made sure the neg one made a good connection to the engine. -Put a strap from the back of the bed to the frame. -Another strap from back of the cab to the frame. -Made sure I had a good ground to the cab from the back of the engine. -Placed another strap from radiator support to the battery neg post. All my light gremlins went away and my charging gauge started working again.

10-09-2011, 08:04 PM	#3
bmfm64 Registered User Join Date: May 2011 Location: Covington, Wa Posts: 5,240	Re: passenger side tail light I'd definitely check grounds but it sounds like the wire going to the taillight on that side has a break. Usually if a ground is bad the whole back end quits working or functions erratically. I would start at the connection under the rear of the truck where the rear harness connects to the main harness, figure out which one is the park light wire (brown I think) and follow it until you find the break. If the drivers side works there is a break because the same wire feeds all the park lights and plate light.

10-09-2011, 08:46 PM	#4
68Gold/white Registered User Join Date: Sep 2011 Location: Ark City, Kansas Posts: 3,324	Re: passenger side tail light I've had similar problems, trying to remember what all was wrong..... Check the connection at the socket area. seems like that was a problem w/ mine. If the pass side has a problem, check the other side, while you are having all this fun... You can't have too many grounds, anywhere on any vehicle. If you've never completely looked over your wiring, as bmfm stated, you need to look it over, it's not too difficult, there's a harness that's on the frame rail.

10-09-2011, 08:58 PM	#5
big_al_71 Registered User Join Date: Jun 2008 Location: South Florida Posts: 11,375	Re: passenger side tail light This happened to ny truck last week after we finished installing my autometer gauges my truck has all the wires brand new and i mean the complete truck extra grounds and all the problem was in the dash harness there is a plug that connects to another harness that plug was slightly loose we reconnected it and the rigjt side lamps started working we tie wrapped it so it wont come apart again. Check that plug is right behind the speedo head just above the fuse box. Posted via Mobile Device __________________ Get your facts first, and then you can distort them as much as you please!!!!!. Sylvester's build thread >>>http://67-72chevytrucks.com/vboard/s...ht=big+rebuild

10-09-2011, 11:29 PM	#6
rick0312 Registered User Join Date: Jan 2006 Location: Warrington, PA Posts: 403	Re: passenger side tail light line had a break in it. luckily it was close to the light. now I hope i remember how to put everything back. PO hack in a trailer harness so that is making things a bit tricky. __________________ 69 C10 LWB GM 350 crate motor, 3.73 rearend

10-09-2011, 11:33 PM	#7
68gmsee Active Member Join Date: Jul 2007 Location: Centrally located between Houston, Austin and Waco. BCS area. Posts: 7,947	Re: passenger side tail light Glad you found the problem. I forgot to add on my post that the grounding were a first step before looking for other gremlins. I chased a problem for days until I found it was bad grounding that were making my lights act up. They would work sometimes and then they would not work. Really made no sense at the time.

10-10-2011, 10:43 PM	#9
rick0312 Registered User Join Date: Jan 2006 Location: Warrington, PA Posts: 403	Re: passenger side tail light hooked light back up but must ahve done something wrong. all lights come on, but when I hit the brake the passengerside brake light goes out!!!. what did I do wrong?.thanks __________________ 69 C10 LWB GM 350 crate motor, 3.73 rearend

10-10-2011, 10:49 PM	#10
MacGyver72 Registered User Join Date: Sep 2011 Location: Greencastle, IN Posts: 132	Re: passenger side tail light That DEFINITELY sounds like a ground problem to me. It also can be related to your trailer light hookup. The others are right. Ground everything you can.

10-11-2011, 12:56 AM	#11
rick0312 Registered User Join Date: Jan 2006 Location: Warrington, PA Posts: 403	Re: passenger side tail light all is working fine now. i removed the trailer harness and cleaned up the grounds. thanks for all the input. you guys are the best! __________________ 69 C10 LWB GM 350 crate motor, 3.73 rearend

10-11-2011, 12:58 AM	#12
MacGyver72 Registered User Join Date: Sep 2011 Location: Greencastle, IN Posts: 132	Re: passenger side tail light Excellent! Glad you got it fixed.



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