Brake lights always on - switch, right ?

[Greg D.]

I just noticed my 72 now has the red portion of the tail lights always on (lights off), and when you press the brake pedal nothing changes... so it looks like brake lights "always on" but at 1/2 power or so, not quite like the brakes are on... That's new ;-) I imagine the brake light switch at the master cylinder is defective ? Just wanted a second opinion before I order one ! Is it a special part for 72 (I have the weird flashing handbrake light that doubles as a brake failure light I think)....

[Chuck Miller]

Greg,

My '73 did the same thing...

Take out the carpet and foot board and see if the Bakelite switch has broken off its mounting flange at the peddle box (bearing bracket)...Therefor leaving the switch open...

If it's a clean break you can unscrew the flange glue it back together with epoxy... ask me how I know...

I fixed mine in a parking lot about 8 years ago... the glued one is still in use......

... or get a new switch

Hope this helps,
cm

[fizeus]

Greg,
mine had same problem. The contact simply slipped off the pedal washer.

I bended it and fixed.

here is the tread http://forums.pelicanparts.com/porsc...ht-switch.html

Just in case you have to replace your keep in mind that the original part is made by Wittrin (www.wittrin.com)

hope this help

[edmayo]

Just disconnect the wires from the switch,,,see if the lights go out !!!

[Greg D.]

Thank you guys, very helpful !

[Greg D.]

Fixed. But I'd like to double check I understand this...

As the switch was, there was no way it EVER worked... I'm wondering now if that was messed up months ago when my mechanic's assistant cleaned up my pedal cluster area... I know nothing about those switches so pardon my ignorance and the blurry pic !

There's a lip on the master cylinder push rod. The switch "trigger" (at the end of the FRONT arrow) only works one way - that is if you pull it towards you (in picture) the brake lights goes off. It is sprung to retract towards the front of the car, when the brake pedal is pushed it has freedom to do so and triggers the brakes... Is that correct ?



The trigger as I found it was positioned behind the lip (back)... So it would never actuate because no way it could be pulled on... On a hunch I detached it and reattached it so that the trigger is now in front of the lip (front, on pic). Now it works, according to my assistants (as far as you can trust a 5 y old), I have brake lights again when braking and no brake lights when not braking... (before they were always on)

Did I get this right ? Does this trigger "slip" possibly if there is some play in the bushings, or was it reinstalled wrong? Anyway, I think I got it....

[fizeus]

Greg,
I think you fixed it in the right way.

The switch arm has to be in front of the lip buecause it has a return spring that close the circuit and make your stop lights goes on.
When you push the brake pedal the switch arm should goes down by itself activating lights.
When you release the brake pedal the lip goes up dragging the switch arm and then opening the circuit (lights off).

While you’re in there check for the pedal cluster. The brake pedal shouldn’t have left-to-right play: if it has some you should consider rebuilding or replacing worn pedal cluster parts (generally cheap fix).

I told this because if you have pedal play the arm can slip back again.

As told in previous post I had your exact same problem: my switch arm was gone behind the pedal lip keeping the brake lights always on: I moved it in front of the pedal lip and also bent it a little to make sure it can’t escape anymore.

I think you can consider the problem solved. You and your assistant should have a beer (or probably better a beer and an orange juice). :-)