Brake lights rh not working?

The Era of The Square Body Racing Comets
Lou's Comet
Posts: 1539
Joined: Sat Nov 26, 2011 8:56 pm
Location: Jeannette, Pa.

Re: Brake lights rh not working?

Post by Lou's Comet »

luc3ch wrote:I checked that I do have power coming into the brake switch. Not sure it's coming out.

The new fuse is still good but I'm not sure it has good contact with its terminal clips.

Also when I jumped the brake terminals with a screwdriver it still didn't light up the brakes.

More work tomorrow.
If you have power going into the brake switch then your fuse is getting good contact. And I would think no problem on the power supply for brake switch.

And when you jumped the terminals to the brake switch you were bypassing it , took it out of the equation. So if you still didn't have brake lights then your problem is the wire that goes from the brake switch to the t/s switch or you got a bad t/s switch :(

Lou

Edit: just wanted to add. What I would do next is pull the steering wheel. Check for power coming from the brake light switch. With the key in the off position press the brake pedal. The green wire (according to the diagram I have) should have power with brake pedal pressed. If it does then wire is good and t/s switch is bad. If there is no power the wire is bad.

If you can't see the color of the wires to test for power from brake switch, then test all terminals on switch to see if one is hot with brake pedal pressed and off when brake pedal is released.

luc3ch
Posts: 122
Joined: Wed Apr 13, 2016 9:11 am

Re: Brake lights rh not working?

Post by luc3ch »

Update: if I jump 12v straight to the green going into the ts switch, the brakes light up.

All the new fuses and the cleaned up fuse block have continuity and get 12v with key on.

The brake switch has 12v at hot terminal al, the time and switch makes contact when pedal depressed.

Still looking for the problem.
1964 Comet Caliente, 302, upgraded to Toploader, front disk brakes ready for 2021 season after the snow melts!

luc3ch
Posts: 122
Joined: Wed Apr 13, 2016 9:11 am

Re: Brake lights rh not working?

Post by luc3ch »

Now I just jumped power into the blue wire of the ts switch. It works: left position lights up left, right lights right.

So somehow I am not getting power into the circuit for brakes or ts.

What can it be?
1964 Comet Caliente, 302, upgraded to Toploader, front disk brakes ready for 2021 season after the snow melts!

Lou's Comet
Posts: 1539
Joined: Sat Nov 26, 2011 8:56 pm
Location: Jeannette, Pa.

Re: Brake lights rh not working?

Post by Lou's Comet »

luc3ch wrote:Update: if I jump 12v straight to the green going into the ts switch, the brakes light up.

All the new fuses and the cleaned up fuse block have continuity and get 12v with key on.

The brake switch has 12v at hot terminal al, the time and switch makes contact when pedal depressed.

Still looking for the problem.
Has to be brake light switch related. You have power going into switch. And when you put power to the green wire on other side of switch your brake lights work. Has to be switch, the connector on switch or the way the switch is mounted

Test for power on both sides (with pedal depressed) of the switch first. When you depress the brakes both wires/terminals on the switch should be hot, have 12V. If both wires are not hot when you press the pedal the switch is bad or how it is mounted is causing a problem.

Take the brake light switch off the car, connect the wires to it and with your hand press and release the switch to see if it works and brake lights go on and off. If it does then there is a problem with the way it is mounted. If not the switch is bad.


If the switch works in your hand then you need to look at how it is mounted.

Did the car come with the the brake light switch on the pedal from the factory or did it have a pressure switch?

For some reason I thought they had pressure switches and not mechanical switches on the pedal, but not sure.

If someone mounted a different type switch it may be adjustable.
Is it stationary the body of switch does not move when brake pedal is pressed? or does the whole (body) of switch move with the brake pedal?

Lou

luc3ch
Posts: 122
Joined: Wed Apr 13, 2016 9:11 am

Re: Brake lights rh not working?

Post by luc3ch »

OK my ts are back. Still not getting brake lights.

I mounted a mechanical switch at the pedal to get rid of the old hydraulic one.

About to pull it and operate manually..
1964 Comet Caliente, 302, upgraded to Toploader, front disk brakes ready for 2021 season after the snow melts!

luc3ch
Posts: 122
Joined: Wed Apr 13, 2016 9:11 am

Re: Brake lights rh not working?

Post by luc3ch »

Here the latest discovery: I get 12v into the bs. But as soon as I try jumping it straight to the other wire the voltage drops to almost nothing. So I am check my connections.

A poor connection can hold voltage with no load but then drop to near zero if it is barely in contact.
1964 Comet Caliente, 302, upgraded to Toploader, front disk brakes ready for 2021 season after the snow melts!

Comechero65
Posts: 1870
Joined: Wed Mar 12, 2014 10:37 pm
Location: Santa Clara, Ca

Re: Brake lights rh not working?

Post by Comechero65 »

As you mention, sounds like there is a bad connection somewhere between fuse block and brake sw for the voltage to drop off like that. If it were a short it would blow the fuse. Remove the bulb at the taillight and do the test again. If the voltage then doesn't drop to zero then at least that verifys the wiring to the bulb is good.
Switching to a mechanical sw will have the same issue is unless in the process of changing it fixes the bad connection. Time to check all connections between those two points.
Ron
Image

luc3ch
Posts: 122
Joined: Wed Apr 13, 2016 9:11 am

Re: Brake lights rh not working?

Post by luc3ch »

The final deal: I ran a key-on 12v source to the hot side of the brake switch. It is fuse protectedo.

Everything works.

Going to put LEDS and a low current flasher in just to be sure everything stays good.

Woodward is in 2 weeks, this is he last repair before then.
1964 Comet Caliente, 302, upgraded to Toploader, front disk brakes ready for 2021 season after the snow melts!

Lou's Comet
Posts: 1539
Joined: Sat Nov 26, 2011 8:56 pm
Location: Jeannette, Pa.

Re: Brake lights rh not working?

Post by Lou's Comet »

Glad you got it working!

Woodward has always been a cruise I wanted to go to. Hopefully some day I will get to take my Comet there.

Have fun!!

Lou

luc3ch
Posts: 122
Joined: Wed Apr 13, 2016 9:11 am

Re: Brake lights rh not working?

Post by luc3ch »

Come on up Lou and we will go for a ride.
1964 Comet Caliente, 302, upgraded to Toploader, front disk brakes ready for 2021 season after the snow melts!

Lou's Comet
Posts: 1539
Joined: Sat Nov 26, 2011 8:56 pm
Location: Jeannette, Pa.

Re: Brake lights rh not working?

Post by Lou's Comet »

luc3ch wrote:Come on up Lou and we will go for a ride.
Thanks for the invite! Wish I could. Just got back from NC. Need to get busy at work.

Have a safe fun trip.

Lou

luc3ch
Posts: 122
Joined: Wed Apr 13, 2016 9:11 am

Re: Brake lights rh not working?

Post by luc3ch »

My trip is 1 1/2 miles. I live in Royal Oak just east of Woodward. Chose this neighborhood for a reason!
1964 Comet Caliente, 302, upgraded to Toploader, front disk brakes ready for 2021 season after the snow melts!

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