3rd brakelight stays on, brakelights dont work
Thread Starter
Junior Member
Joined: Jun 2006
Posts: 43
Likes: 1
From: St. Marys, Ohio
Car: 1989 Pontiac Formula 350(Maui Blue)
Engine: 355 TPI,accell superram,full roller
Transmission: Street/strip 700R4
Axle/Gears: Australian 9, 3:27 ratio
3rd brakelight stays on, brakelights dont work
Got home tonight after driving my formula, pulled into garage, shut off car, and 3rd brake light stays lit and wont go off. Had my son come out and when i hit brakes, no brake lights light up but 3rd brakelight stays lit all the time no matter what i do. Please help guys?????
I had to pull brakelight 20 amp fuse to get it to shut off so I dont run battery down and screw anything up while it sits.
Dont know if it has anything to do with it, but bout a month ago my cruise quit working with no notice. I know there are 2 switches mounted to bracket. If brakelight switch is bad, why is 3rd brakelight lit all the time?
I shouldnt have anything working, should i ? or is 3rd brakelight and cruise worked off of 1 switch and rear brakes off another? i have running lights when headlights on and turn signals work perfect.
Thanks,
Joe
I had to pull brakelight 20 amp fuse to get it to shut off so I dont run battery down and screw anything up while it sits.
Dont know if it has anything to do with it, but bout a month ago my cruise quit working with no notice. I know there are 2 switches mounted to bracket. If brakelight switch is bad, why is 3rd brakelight lit all the time?
I shouldnt have anything working, should i ? or is 3rd brakelight and cruise worked off of 1 switch and rear brakes off another? i have running lights when headlights on and turn signals work perfect.
Thanks,
Joe
Re: 3rd brakelight stays on, brakelights dont work
Im Chasing this ghost has well..How ever my third light works,turns signal ect.Just my Brakes Tails dont!
So far Ive checked all my bulbs,fuses ,and switchs.
I belive the one with the hose Is just for the cruz,and the other is for the lights.The plug on the bottom of it is the 3rd light,The one with grey and brown wire is for the tail.
Ive heard this problem can be caused in your turn signal switch,But I would like some confirmation/Reassurance from All of You! THX
So far Ive checked all my bulbs,fuses ,and switchs.
I belive the one with the hose Is just for the cruz,and the other is for the lights.The plug on the bottom of it is the 3rd light,The one with grey and brown wire is for the tail.
Ive heard this problem can be caused in your turn signal switch,But I would like some confirmation/Reassurance from All of You! THX
Junior Member
Joined: Jul 2009
Posts: 68
Likes: 0
From: Oregon
Car: 92 GMC Sierra 2500
Engine: 5.7l
Transmission: 4L70
Axle/Gears: GT4 3.73
Re: 3rd brakelight stays on, brakelights dont work
To troubleshoot electrical problems on modern vehicles, you pretty much need a factory service manual set which includes wiring diagrams and locations on the vehicle of various components. Also has detailed troubleshooting instructions. Order this from your dealer or here...
http://www.helminc.com
You would also need to know how to use a multimeter or be willing to learn.
Basically all the wiring is wrapped up in harnesses and hidden, so you can't trace wires and see where they go. So you need the factory manual set to show you the circuit, where connectors are located for this circuit, and terminals and wire colors for the circuit (for testing).
Be aware that the newer vehicles use computer modules for all this stuff. There can be 30 computer modules in a new vehicle and over 70 computer modules in an upscale vehicle.
They use these to reduce wires run in the vehicle. A computer module will be located near switches, then a computer signal is sent over a local area computer network to another computer module near the device, then that module turns on/off the device.
Computer network wiring in the factory service manual diagrams will have a figure 8 around the wires, half a figure 8 (twisted pair wires), or what looks like a can around the wires (shielded). Or it may say Class 2, 3, etc., GMLAN, serial data, etc.
With that said, check ALL fuses, because there could be several computer modules involved between a switch and a device. How to check fuses...
http://www.dinosaurelectronics.com/Test_Fuse.htm
http://www.helminc.com
You would also need to know how to use a multimeter or be willing to learn.
Basically all the wiring is wrapped up in harnesses and hidden, so you can't trace wires and see where they go. So you need the factory manual set to show you the circuit, where connectors are located for this circuit, and terminals and wire colors for the circuit (for testing).
Be aware that the newer vehicles use computer modules for all this stuff. There can be 30 computer modules in a new vehicle and over 70 computer modules in an upscale vehicle.
They use these to reduce wires run in the vehicle. A computer module will be located near switches, then a computer signal is sent over a local area computer network to another computer module near the device, then that module turns on/off the device.
Computer network wiring in the factory service manual diagrams will have a figure 8 around the wires, half a figure 8 (twisted pair wires), or what looks like a can around the wires (shielded). Or it may say Class 2, 3, etc., GMLAN, serial data, etc.
With that said, check ALL fuses, because there could be several computer modules involved between a switch and a device. How to check fuses...
http://www.dinosaurelectronics.com/Test_Fuse.htm
Joined: May 2008
Posts: 867
Likes: 1
From: pawtucket RI
Car: 1986 iroc
Engine: alum. head 350 supercharged
Transmission: 6speed
Axle/Gears: ford 9in 3.90 35 spline moser axles
Re: 3rd brakelight stays on, brakelights dont work
i know the camaro's they have that piece that bolts under the rear deck and to the deck lil metal piece that's for the 3rd brake light to have power 86-90 camaro's open the rear deck and see if the light goes out then start there
Thread Starter
Junior Member
Joined: Jun 2006
Posts: 43
Likes: 1
From: St. Marys, Ohio
Car: 1989 Pontiac Formula 350(Maui Blue)
Engine: 355 TPI,accell superram,full roller
Transmission: Street/strip 700R4
Axle/Gears: Australian 9, 3:27 ratio
Re: 3rd brakelight stays on, brakelights dont work
Thanks for the replies. I will double check all fuses and switches. all seem ok though.
Hey Tom, dont you have a paxton sn on your car? I just came across a sn 92 kit with impeller upgrade and its the polished kit. how long did it take you for install? just curious. the kit is very complete give or take a couple mount bolts.
Thanks,
Joe
Hey Tom, dont you have a paxton sn on your car? I just came across a sn 92 kit with impeller upgrade and its the polished kit. how long did it take you for install? just curious. the kit is very complete give or take a couple mount bolts.
Thanks,
Joe
Re: 3rd brakelight stays on, brakelights dont work
If we could ,lets stay on subject,No offense,But If you do a search thers alot of brake threads with this problem and very few solutions.
One solution Ive read Was when A complete column was changed out.
One solution Ive read Was when A complete column was changed out.
Thread Starter
Junior Member
Joined: Jun 2006
Posts: 43
Likes: 1
From: St. Marys, Ohio
Car: 1989 Pontiac Formula 350(Maui Blue)
Engine: 355 TPI,accell superram,full roller
Transmission: Street/strip 700R4
Axle/Gears: Australian 9, 3:27 ratio
Re: 3rd brakelight stays on, brakelights dont work
Sorry to ruffle your feathers xx, Update: Today i took out brakelight switch and plunger seemed to hang up when i pushed it in while holding it. It went in all the way when i pushed it, but didnt release all the way back out when i took finger off it.
I ordered one from parts store, will be in tomorrow. will keep everyone posted.
This couldnt be my prob since power was getting to rear of car through switch to make my 3rd brakelight stay on all time. if its bad, i shouldnt get anything to work unless one plug for the switch is for 3rd light and other is for brakelights?????? The switch has a plug in on bottom and 1 on side???
I ordered one from parts store, will be in tomorrow. will keep everyone posted.
This couldnt be my prob since power was getting to rear of car through switch to make my 3rd brakelight stay on all time. if its bad, i shouldnt get anything to work unless one plug for the switch is for 3rd light and other is for brakelights?????? The switch has a plug in on bottom and 1 on side???
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Re: 3rd brakelight stays on, brakelights dont work
No worries. LOL,"ruffle my feathers".
I tryed replacing my switch to..didnt work.Hope yours does
I found this through the search engine https://www.thirdgen.org/forums/brak...wont-work.html
Good thread with similar problems.
I tryed replacing my switch to..didnt work.Hope yours does
I found this through the search engine https://www.thirdgen.org/forums/brak...wont-work.html
Good thread with similar problems.
Last edited by MADMAXGTA; Jul 9, 2009 at 01:34 AM.
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