Help with Brake light PLEASE!
Thread Starter
Instructor
Joined: Mar 2010
Posts: 155
Likes: 4
From: Florida
Help with Brake light PLEASE!
I hope someone will be able to point me in the right direction.
Took the car ('71) out to a car show Tuesday night when I realized the brake lights were not working, I have parking lights. The directionals work as do the hazard lights.
So I checked the fuse it looked ok but installed a new one anyway, didn't help. Ordered and installed a new Brake light Switch what a PIA and guess what? Still no brake lights..
Could it be the turn signal switch? even though the signals work?
I'm at a loss at where to go next..
Tom D.
Took the car ('71) out to a car show Tuesday night when I realized the brake lights were not working, I have parking lights. The directionals work as do the hazard lights.
So I checked the fuse it looked ok but installed a new one anyway, didn't help. Ordered and installed a new Brake light Switch what a PIA and guess what? Still no brake lights..
Could it be the turn signal switch? even though the signals work?
I'm at a loss at where to go next..
Tom D.
Melting Slicks
Joined: Apr 2007
Posts: 3,189
Likes: 111
From: Tolland CT
Did you check the bulbs?
I'm pretty sure they have two elements.
I don't recall which element the flashers go to, parking light or brake, think they may go to the parking light element.
Maybe check the connector where the rear harness attaches to the front? Longshot.
Is the brake light switch being pressed in far enough when you step on the pedal?
I'm pretty sure they have two elements.
I don't recall which element the flashers go to, parking light or brake, think they may go to the parking light element.
Maybe check the connector where the rear harness attaches to the front? Longshot.
Is the brake light switch being pressed in far enough when you step on the pedal?
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,116
From: Crossville TN
Since the hazard signals work, the bulbs and wiring are OK...except for the brake light switch/wiring that feeds into the wiring going to the rear of the car. Did you properly adjust for the actuator button on the new switch? Did you use an ohmmeter to check that the new switch actually works [lots of 'new' stuff from China doesn't even work out-of-the-box]? When hooked up, can you get 12 vdc measurement coming out of the new switch? (if so, the wiring is OK and the switch is OK, but the signal is not getting to the 'feed' wire going to the lights. Must be a break in the wiring somewhere after the switch.) Good luck with your diagnosis. 
Team Owner
Joined: Jul 1999
Posts: 26,545
Likes: 46
From: Huntersville NC
I would troubleshoot by having someone sit in the drivers seat and press on the brake pedal while I checked the grounds in back near the tail lights. hmmmm... might need a 3rd person to let me know if the brakelights go on. If neither side is going on I would say its unlikely to be the bulb(s). With our cars it seems like most electrical probs are caused by bad grounds..
(gross generalization, but some truth to it)
Last edited by PRNDL; Aug 7, 2010 at 11:35 AM.
Melting Slicks
Joined: Apr 2007
Posts: 3,189
Likes: 111
From: Tolland CT
If it were a ground issue I doubt the other lights would work. Seems more like 12v isn't getting to the brake lights.
Race Director
Joined: May 2006
Posts: 16,528
Likes: 53
From: Dayton, Ohio
This should be pretty easy for you to check.
Find the turn signal connector (harmonica connector) attached to the lower steering column.
Step on the brake pedal , check the white wire for power (white wire is all the way to 1 end of the connector next to the green)
If you have power at the white the brake switch is working
With the brake pedal still down check the green and yellow wires for power
If you have no power on the green and yellow then the turn switch is shot
*******
Info- the turn signals , hazards and brake lights all use the same filament in the same bulb and they all use the same 2 wires (green and yellow) to get to the rear of the car from the turn signal switch.
For the hazards - power goes up the column on the BROWN wire and comes down (after going through the turn switch) on the green and yellow
For the turn signals- power goes up the column on the PURPLE and comes down on the green and yellow
For the brake lights- power goes up the WHITE wire and comes down the green and yellow
Find the turn signal connector (harmonica connector) attached to the lower steering column.
Step on the brake pedal , check the white wire for power (white wire is all the way to 1 end of the connector next to the green)
If you have power at the white the brake switch is working
With the brake pedal still down check the green and yellow wires for power
If you have no power on the green and yellow then the turn switch is shot
*******
Info- the turn signals , hazards and brake lights all use the same filament in the same bulb and they all use the same 2 wires (green and yellow) to get to the rear of the car from the turn signal switch.
For the hazards - power goes up the column on the BROWN wire and comes down (after going through the turn switch) on the green and yellow
For the turn signals- power goes up the column on the PURPLE and comes down on the green and yellow
For the brake lights- power goes up the WHITE wire and comes down the green and yellow
Thread Starter
Instructor
Joined: Mar 2010
Posts: 155
Likes: 4
From: Florida
Thanks for all the info,
Checked power to the brake switch and had approx 12VDC, next I checked the grounds at the tail lights which looked good.
Next is what Roger said.
Hopefully it's the turn signal switch.
Checked power to the brake switch and had approx 12VDC, next I checked the grounds at the tail lights which looked good.
Next is what Roger said.
Hopefully it's the turn signal switch.
