no brake lights - The 1947 - Present Chevrolet & GMC Truck Message Board Network

dremmick · 10-21-2014, 10:09 PM

My lights tail lights are acting really weird. I have no running lights and the only way the running lights are on is when I turn the blinker on with the vehicle off. When the vehicle is running I turn the blinkers on and the L and R blinkers flash at the same time. Anyone got any idea what's going on?

**Grumpy old man** · 10-21-2014, 10:33 PM

check all your ground wires ,there are numerous threads on problematic lights and your grounds are where you start .

**chiefcfd** · 10-21-2014, 10:35 PM

Unplug the rear harness on the firewall and check each wire with a test lite. Then you know where to start. If everything checks out there look at the rear harness. I had one that got on the exhaust and melted. Caused all kinds of strange lights.

dremmick · 10-21-2014, 10:58 PM

it looks like there is a brown wire and 3 green ones? I know the Brown is the power supply. What are the others?

**VetteVet** · 10-22-2014, 12:36 AM

Quote:

Originally Posted by dremmick

it looks like there is a brown wire and 3 green ones? I know the Brown is the power supply. What are the others?

You should have a brown wire for the tail lights, a dark green wire for the right turn/brake light, a yellow wire for the left turn/brake light, and a light green wire for the back-up lights.

There should be a mid frame connector which has two browns and two light green for the two tail lights and the two back-up lights and the brown wires will also go to the license plate light.

I have a 67 c 10 so I will double check mine and if it is different than that I will post back. VV

old Chevy guy · 10-23-2014, 05:45 PM

Sounds like ground issues to me also

dremmick · 10-28-2014, 07:39 PM

I checked voltage at rear connector in frame. The wire coming from the firewall to this connector are working fine. What could be wrong with the wires from this connector to the taillights? We're are the taillights grounded?

10-21-2014, 10:09 PM	#1
dremmick Registered User Join Date: Dec 2007 Location: West Fargo, ND Posts: 31	no brake lights My lights tail lights are acting really weird. I have no running lights and the only way the running lights are on is when I turn the blinker on with the vehicle off. When the vehicle is running I turn the blinkers on and the L and R blinkers flash at the same time. Anyone got any idea what's going on?

10-21-2014, 10:33 PM	#2
Grumpy old man Senior Member Join Date: Dec 2013 Location: Gods country East,Tn Posts: 8,545	Re: no brake lights check all your ground wires ,there are numerous threads on problematic lights and your grounds are where you start .

10-21-2014, 10:35 PM	#3
chiefcfd Senior Member Join Date: Oct 2010 Location: Cadiz, Ky Posts: 514	Re: no brake lights Unplug the rear harness on the firewall and check each wire with a test lite. Then you know where to start. If everything checks out there look at the rear harness. I had one that got on the exhaust and melted. Caused all kinds of strange lights. __________________ 1972 Chevy LWB Roadster 1999 Chevy Silverado 2wd 2015 Chevy High Country 4x4 Crew Cab

10-21-2014, 10:58 PM	#4
dremmick Registered User Join Date: Dec 2007 Location: West Fargo, ND Posts: 31	Re: no brake lights it looks like there is a brown wire and 3 green ones? I know the Brown is the power supply. What are the others?

10-23-2014, 05:45 PM	#6
old Chevy guy Registered User Join Date: Apr 2007 Location: Foster Rhode Island Posts: 1,176	Re: no brake lights Sounds like ground issues to me also

10-28-2014, 07:39 PM	#7
dremmick Registered User Join Date: Dec 2007 Location: West Fargo, ND Posts: 31	Re: no brake lights I checked voltage at rear connector in frame. The wire coming from the firewall to this connector are working fine. What could be wrong with the wires from this connector to the taillights? We're are the taillights grounded?



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