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View Full Version : No brake lights on an 88 GTC Convertible!



daytonachad
04-18-2006, 06:30 PM
OK,
I have some questions....:confused:
my 88 GTC vert has no brake lights, the bulbs are fine and so is the fuse. (the 4 way flashers work in all 4 rear lights, and the brake fuse is also used for the dome lamps, which work)
I had to remove the drivers seat and lay on my back to get to the brake pedal/brake switch NOT easy to do when your my size and with a bad back!:censored:
ANYWAY, my questions:
1. What is the EASIEST/quickest way to get the brake switch out? Is it even feasible to try with the column still in the car?
2. Are there any other thoughts as to what may be causing the no brake lights? (other than a bad switch?)
Thanks!
Chad

Charger R/T
04-18-2006, 06:59 PM
It could also be a bad turn signal switch. I'm not saying your brake light switch is not bad but you asked what else could be bad. The way the circuit works is power goes into the brake light switch. You hit the brake power comes out and goes to the brake light switch. The brake light switch then determines if the rear bulb will light for brake or turn signal. Since your turn signals work the wiring from the turn signal switch to the rear lights is good. The only problems could be:
1. no power to the switch (I know you said the fuse is good and something else on the circuit works but it doesn't mean power is there.
2. the brake light switch is bad.
3. wiring from the brake light switch to the turn signal switch is bad.
4. The turn signal switch is bad.
Tim

daytonachad
04-18-2006, 09:48 PM
Hi Tim,
I'll check them out... thanks for the ideas!
Chad

midohiomoparsource
04-23-2006, 05:13 PM
Take a test light to ALL the fuses with key on.

I know it may be a waste of some time, but I worked on a New Yorker a couple of years ago, and the ATC would not work, the fuse it showed in the book was good. I worked on it for two days trying to figure out what was wrong. Finally I checked ALL fuses, and found that the reverse lights fuse was blown. Changed it and the ATC started working!! Nothing pointed to those two having anything to do with eachother, but somehow they do.

This really has nothing to do with your ?, but it is an idea that the fuses aren't exactly how they say maybe as in my case.

cordes
04-23-2006, 05:29 PM
I would check the grounds in the bulb sockets. I had no brake lights on my right side in the shadow due to a bad ground.

daytonachad
04-23-2006, 07:37 PM
Take a test light to ALL the fuses with key on.

I know it may be a waste of some time, but I worked on a New Yorker a couple of years ago, and the ATC would not work, the fuse it showed in the book was good. I worked on it for two days trying to figure out what was wrong. Finally I checked ALL fuses, and found that the reverse lights fuse was blown. Changed it and the ATC started working!! Nothing pointed to those two having anything to do with eachother, but somehow they do.

This really has nothing to do with your ?, but it is an idea that the fuses aren't exactly how they say maybe as in my case.
I checked all teh fuses, even swapped teh ones around for the brake lights and another 20 amp fuse, it didnt help, not surprising as other things (such as dome lights) still worked on the same fuse as the brake lights.
Thanks for the ideas though!

daytonachad
04-23-2006, 07:39 PM
I would check the grounds in the bulb sockets. I had no brake lights on my right side in the shadow due to a bad ground.
Thats a thought, but why would the flasher and 4 ways work fine?
Any ideas?
I actually pulled the drivers seat out, so I could lay down and get under the dash, it looks like the brake switch is frozen.
As soon as I get the time I am going to further investigate that.
Thanks
Chad

cordes
04-23-2006, 07:50 PM
Thats a thought, but why would the flasher and 4 ways work fine?
Any ideas?
I actually pulled the drivers seat out, so I could lay down and get under the dash, it looks like the brake switch is frozen.
As soon as I get the time I am going to further investigate that.
Thanks
Chad


I havent the foggiest, as my flashers and brake lights worked to a certian extent. when the head lights would come on the brake lights would go out on the right side. It was funky, but fixing the ground on the right side worked.

daytonachad
04-23-2006, 08:02 PM
electrical problems can be strange....
I'll check into it...
Thanks
Chad

Charger R/T
04-23-2006, 09:02 PM
I havent the foggiest, as my flashers and brake lights worked to a certian extent. when the head lights would come on the brake lights would go out on the right side. It was funky, but fixing the ground on the right side worked.
The reason your lights sort of worked until you turned on the headlights is if the ground is bad the parking light filiment and the turn signal filiment share the ground terminal on the bulb and the turn signals backfeed through the parking light filiment and sort of found a ground through the bulbs on the other side of the car. When you turn on the headlights you take that sort of ground away and put power on that wire. The light goes out. Usually the flashers will also seem to work too but flash when it should be off and is on when it should be off. If you turn the headlights on and the 4ways at the same time the sides usually will flash out of phase.
Tim

cordes
04-23-2006, 09:16 PM
The reason your lights sort of worked until you turned on the headlights is if the ground is bad the parking light filiment and the turn signal filiment share the ground terminal on the bulb and the turn signals backfeed through the parking light filiment and sort of found a ground through the bulbs on the other side of the car. When you turn on the headlights you take that sort of ground away and put power on that wire. The light goes out. Usually the flashers will also seem to work too but flash when it should be off and is on when it should be off. If you turn the headlights on and the 4ways at the same time the sides usually will flash out of phase.
Tim

Now that is insightful. I was just happy to stumble on the problem after 4hrs. Thanks for the explanation.

Charger R/T
04-24-2006, 08:25 PM
your welcome. basic wiring is my speciality. At work I use soldering irons and test lights most of the time and some of the other guys hang truck brakes and clutches. They think that I get the hard stuff LOL.
Tim

daytonachad
04-28-2006, 06:33 PM
The saga continues:

I tried getting the brake switch out, almost impossible with the steering column in...
Those that know me..picture this.. I had to pull the drivers seat out, laying flat on my back my legs were up and over the back seat so I could see under the dash... I could NOT get the:censored: brake switch out... SO, I removed the bottom of the dash, pulled the steering column (again all from flat on my back under the dash, feet dangling over the lowered convertible top) I'm so glad I had my garage door open, my neighbors probably think I'm nutz... they may be right, but anyway...
after unplugging all the wires and connectors from the steering column, pulled it out, still couldnt get the switch out, had to pull the rod off the brake pedal, still had to fight the metal piece that activate the brake lights as it moves away from the brake switch. so I finally get it out and start calling parts stores, it was about 6 PM Tuesday evening. Nobody had one (imagine that) I was going to try swapping the column with my 89 but found different part #s between the 88 and 89, so I called my buddy back @ Napa and ordered one, it was like $30 + tax. I got it Thursday, my back was still killing me from my floor(pan) exercises. So tonight I get home early from work, put the new switch and had the GF come out, I hooked the battery back up (steering column still out of the car) and had her hit the brakes... only the 3rd brakelight came on (a vast improvement but still need ALL my brake lights, thats when I thought back to this thread and what Tim said,

It could also be a bad turn signal switch. I'm not saying your brake light switch is not bad but you asked what else could be bad. The way the circuit works is power goes into the brake light switch. You hit the brake power comes out and goes to the brake light switch. The brake light switch then determines if the rear bulb will light for brake or turn signal. Since your turn signals work the wiring from the turn signal switch to the rear lights is good. The only problems could be:
1. no power to the switch (I know you said the fuse is good and something else on the circuit works but it doesn't mean power is there.
2. the brake light switch is bad.
3. wiring from the brake light switch to the turn signal switch is bad.
4. The turn signal switch is bad.
Tim
Well I figured I would go ahead and put the column back in and hope for the completed circuit to give me ALL my brakelights, I disconnected the battery again (didnt want to cause a short and blow the air bag, yes it's an 88 GTC turbo convertible and it does have an airbag) and about 1/2 hour later had it all back together.
Well $32 and a VERY stiff back I have replaced the brake light switch... guess what....:confused:
I have brake lights now :dancingbana:
It wasn't that bad, I should have and would highly recomend removing the column, it was MUCH easier and faster than trying ot pull the switch with the column in!
Thanks to everyone for their help!
Chad
Now I need to go for a cruise in my convertible, it will be nice not worrying (as much) about getting hit from behind ;)

cordes
04-28-2006, 06:50 PM
Wow, that sounds like a rough one. Glad you got that figured out though.

Charger R/T
04-29-2006, 04:53 PM
good deal glad it all worked out. The third light is wired right from the brake light switch since it only works with the brakes and doesn't flash with the signals.
Tim

daytonachad
05-01-2006, 10:07 AM
yeah, it was weird....
No I just need to sell the car...
I am REALLY wanting to get my T2 GTC car back on the road!