Brake light issues ( help) - The 1947 - Present Chevrolet & GMC Truck Message Board Network

7d1truckguy · 12-17-2013, 10:58 AM

I have a 1971 gmc 2wd the right brake light is out as is the rear side marker blinker, I replaced the bulb, you take your foot off of the brake and the parking lights work fine, Could it be the turn signal switch as it will not light up on the dash when I turn the right blinker on ANY HELP WOULD BE GREAT, THANKS 7d1truckguy (Marc)

**TBONE1964** · 12-17-2013, 11:05 AM

Quote:

Originally Posted by 7d1truckguy

I have a 1971 gmc 2wd the right brake light is out as is the rear side marker blinker, I replaced the bulb, you take your foot off of the brake and the parking lights work fine, Could it be the turn signal switch as it will not light up on the dash when I turn the right blinker on ANY HELP WOULD BE GREAT, THANKS 7d1truckguy (Marc)

The first thing I would check is your ground connection for the right side tail light housing.

PanelDeland · 12-17-2013, 11:06 AM

First things first.Try checking all the lights to see if you have good grounds.Many light problems on these trucks are grounding faults.Next look over the wiring in the rear.A lot of the problems are associated with people (known as PO "Previous Owners") rewiring,usually for a trailer plug.If you find these are OK a test light and follow the circuit.Many times it is the turn signal switch but if the rest of the wiring isn't up to par,it might not solve the problem.There is a wiring diagram if you do a search you can find the one for your truck.

68gmsee · 12-17-2013, 11:20 AM

Agree to install grounds even if you find another issue. Old bolts and grime no longer proved a good path to battery ground.

I had some weird light problems with my 68. Brake lights, taillights and signal lights worked erratically. I installed bulbs all around and a couple of bulb housings that looked corroded. What finally fixed it was installing a bunch of ground straps on the truck.

From bed to the frame at the rear
Under the cab to frame
Radiator support to battery negative
Made sure I had a good battery ground cable to engine
Replaced the engine to cab ground behind the engine
For good measure, a ground strap from engine to frame

Maybe overkill but even the headlights were brighter and amp gauge started working properly.

12-17-2013, 10:58 AM	#1
7d1truckguy Registered User Join Date: Jul 2013 Location: warren oregon Posts: 117	Brake light issues ( help) I have a 1971 gmc 2wd the right brake light is out as is the rear side marker blinker, I replaced the bulb, you take your foot off of the brake and the parking lights work fine, Could it be the turn signal switch as it will not light up on the dash when I turn the right blinker on ANY HELP WOULD BE GREAT, THANKS 7d1truckguy (Marc)

12-17-2013, 11:06 AM	#3
PanelDeland I am a Referee of life. Join Date: Jun 2000 Location: Greensboro N.C. Posts: 13,993	Re: Brake light issues ( help) First things first.Try checking all the lights to see if you have good grounds.Many light problems on these trucks are grounding faults.Next look over the wiring in the rear.A lot of the problems are associated with people (known as PO "Previous Owners") rewiring,usually for a trailer plug.If you find these are OK a test light and follow the circuit.Many times it is the turn signal switch but if the rest of the wiring isn't up to par,it might not solve the problem.There is a wiring diagram if you do a search you can find the one for your truck. __________________ The 47-present Chevrolet and GMC Truck Message Board Network,it's owners,moderators,members,and associates of any type should not be held responsible for my opinion. You can't fix stupid,not even with duct tape. "My appearance is due to the fact that "GOD" does punish you for having too much fun!" Barrett-Jackson has perfected alchemy,they make rust into gold! "You can lead a horse to water but you can't saddle a duck" "Cleverly disguised as a 'Responsible Adult' "Sometimes your Knight in shining armor is just a retard in tinfoil"

12-17-2013, 11:20 AM	#4
68gmsee Active Member Join Date: Jul 2007 Location: Centrally located between Houston, Austin and Waco. BCS area. Posts: 7,947	Re: Brake light issues ( help) Agree to install grounds even if you find another issue. Old bolts and grime no longer proved a good path to battery ground. I had some weird light problems with my 68. Brake lights, taillights and signal lights worked erratically. I installed bulbs all around and a couple of bulb housings that looked corroded. What finally fixed it was installing a bunch of ground straps on the truck. From bed to the frame at the rear Under the cab to frame Radiator support to battery negative Made sure I had a good battery ground cable to engine Replaced the engine to cab ground behind the engine For good measure, a ground strap from engine to frame Maybe overkill but even the headlights were brighter and amp gauge started working properly. __________________ 68 GMC 250/3 speed Saginaw p/b p/s 69 Chevy 350/350 currently in pieces still lookin for a cab 06 Trailblazer I just want a vehicle that I can work on, that won't talk to me, leave error msgs or keep track of how I drive...



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