No Brake Lights - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**Already Gone** · 03-30-2012, 01:59 AM

Okay my new ( to me ) 69 CST has no brake lights and the left rear signal light doesn't flash either. The taillights, back up lights, headlights and front signal lights work as they should. Do you think its my brake light switch that is keeping my brakelights from working? What is really baffling me is the one rear ( drivers side) signal light that doesnt flash. I already put in a new 1157 (what was in it before) bulb and that didn't help. Any ideas?

northerngmc · 03-30-2012, 10:36 AM

Have you checked your ground straps? When I bought my 69 GMC I was having all sorts of electrical gremlins and someone mentioned ground straps. Well I could not find any on the box or cab and I put a couple on. Most problems were gone and the other problems were consistent them and I was able to fix them.

Jon Scully · 03-30-2012, 11:22 AM

I second the grounds, also take the housing out and clean the screws that hold it in, this helps with the grouds.

DorianB · 03-30-2012, 03:28 PM

grab a brake light switch from any autozone or pep boys type place.. (They are $7), if the one you have turns out to be good, it's not bad to have a spare

Did it have any trailer hitch wiring? Those seem notorious for falling apart and taking lights with them

**Classic Heartbeat** · 03-30-2012, 05:09 PM

I would test your brake light switch at the peddel, but it sounds like you have a couple of problems going on. It kind of sounds like you may have a grounding issue, or just bad wiring. Over the years people usualy hooked up some sort of trailer wiring and you would be suprised how bad that can get. I would check the wiring for brakes or frays all the way from the firewall where it plugs in to the bulbs in the rear. This is actualy 2 different harnesses, but are the most likely to be dammaged. Any brakes, frays or splices, I would replace the wiring. Repairing it could get you buy for now, but ultimately I would replace the harnesses. WES

Lifetime Project 72 · 03-30-2012, 05:27 PM

I`ve had the same issues on my GMC.Each time its occurred has been the same thing,that one of the wires either from the rear harness or the main harness running down the frame,has worn through some and has shorted out on the frame.Check for any wear on the wiring where it maybe rubbing on the frame.Wire loom is great preventive maintenance for this.
Chris

03-30-2012, 01:59 AM	#1
Already Gone 70+ ( Old Skool Club ) Join Date: Nov 2003 Location: Saskatoon, Saskatchewan ,Canada Posts: 9,139	No Brake Lights Okay my new ( to me ) 69 CST has no brake lights and the left rear signal light doesn't flash either. The taillights, back up lights, headlights and front signal lights work as they should. Do you think its my brake light switch that is keeping my brakelights from working? What is really baffling me is the one rear ( drivers side) signal light that doesnt flash. I already put in a new 1157 (what was in it before) bulb and that didn't help. Any ideas? __________________ 1972 C10 Custom/Deluxe 613 Highlander 406/700R4 1999 White Tahoe LS 4x2 with Z56 Police Package 1992 K1500 GMC Suburban Members I have personally met: MusicMan70 - HeavyD - ChewyChevy67 - StingRay -71SWB4x4 - 67 Burb - DeadheadNM - too much stuff - bc65 - das601 " Circumsatances Do Not Change Responsibility " " The Sky is not the Limit, Your Mind is." Marilyn Monroe .. RIP Charlie Watts 1941 - 2021

03-30-2012, 10:36 AM	#2
northerngmc Registered User Join Date: Jan 2004 Location: Whitehorse YK Canada Posts: 2,651	Re: No Brake Lights Have you checked your ground straps? When I bought my 69 GMC I was having all sorts of electrical gremlins and someone mentioned ground straps. Well I could not find any on the box or cab and I put a couple on. Most problems were gone and the other problems were consistent them and I was able to fix them. __________________ Blaine 59 GMC 9314 a.k.a. Whoopee 68 C20 50th Anniversary a.k.a. The Rat http://www.flickr.com/photos/northerngmc/ http://www.members.tripod.com/P-wee/index_032.htm 1.61803 is one H of a lot better than 3.14159, no really it is!

03-30-2012, 11:22 AM	#3
Jon Scully Registered User Join Date: Jan 2011 Location: Thunder Bay Ontario Posts: 97	Re: No Brake Lights I second the grounds, also take the housing out and clean the screws that hold it in, this helps with the grouds.

03-30-2012, 03:28 PM	#4
DorianB Registered User Join Date: Apr 2010 Location: Buford, Ga Posts: 205	Re: No Brake Lights grab a brake light switch from any autozone or pep boys type place.. (They are $7), if the one you have turns out to be good, it's not bad to have a spare Did it have any trailer hitch wiring? Those seem notorious for falling apart and taking lights with them

03-30-2012, 05:09 PM	#5
Classic Heartbeat Project Junkie! Fishing Poor!! Join Date: Dec 1999 Location: Olympia,Wa. 98512 Posts: 10,766	Re: No Brake Lights I would test your brake light switch at the peddel, but it sounds like you have a couple of problems going on. It kind of sounds like you may have a grounding issue, or just bad wiring. Over the years people usualy hooked up some sort of trailer wiring and you would be suprised how bad that can get. I would check the wiring for brakes or frays all the way from the firewall where it plugs in to the bulbs in the rear. This is actualy 2 different harnesses, but are the most likely to be dammaged. Any brakes, frays or splices, I would replace the wiring. Repairing it could get you buy for now, but ultimately I would replace the harnesses. WES __________________ On-line catolog Classic Heartbeat Pickup Parts WEHEPP@comcast.net Call us Toll Free (888) 338-2502 Like Us on Facebook No appointment necessary. 72 BB Chevy Custom Deluxe / Custom Camper 67 I-6 (Soon to be 5.7 LS1) Panel 68 BB Chevy Short Bed 72 6.0 LQ9 Short Bed Chevy 4X4 Olympia's fastest growing truck parts supplier. Olympia's home for Wayward Chevys

03-30-2012, 05:27 PM	#6
Lifetime Project 72 Registered User Join Date: May 2011 Location: Cobourg Ontario Canada Posts: 35	Re: No Brake Lights I`ve had the same issues on my GMC.Each time its occurred has been the same thing,that one of the wires either from the rear harness or the main harness running down the frame,has worn through some and has shorted out on the frame.Check for any wear on the wiring where it maybe rubbing on the frame.Wire loom is great preventive maintenance for this. Chris

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