914 parking brake wiring question

[jimbeaux911]

OK so I am restoring a 1971 914 project that I bought already dissassembled.

I am close to being done, and am getting all the electrical stuff working. ALL good except when the car is turned on, the flashes are always on. Its not the switch or relay as all working good. Turn signals are fine as well.

Someone pointed me to the parking brake contact switch. they implied if this is not correct, it will cause the flashers to flash. as a warning the brake is on?

Does this sound correct?

and if so, since mine does not have a parking brake switch or wire, any ideas how to proceed?

as always, any help is greatly appreciated!

[Dave at Pelican Parts]

The parking brake contact switch will be under the handbrake handle. It gets pressed by a tab on the bottom of the handle, breaking the circuit. When the handle is not pushing down on the switch, it is spring-loaded to close and to short the wire going to it to ground.

If the wire going to the switch gets shorted to ground in any other way, the light will blink.

There is another wire that goes to a switch in the master cylinder. There is a mechanism in the MC that detects a pressure imbalance between the front and rear brake circuits. When that is detected, the switch shorts that wire to ground. (Usually to the brown wire that also connects to the switch, sometimes to the threads of the switch into the master cylinder.) Almost all of those switches will stay closed once they are closed, and must be reset by pressing a button on the switch. The brown/white wire going to that switch is tied to the brown/white wire going to the handbrake handle switch, so when it does get shorted to ground it will also turn the blinking light on.

This is intended to warn the driver when a brake system failure (e.g., ruptured line, badly boiled fluid, etc.) has happened. In practice, it is usually turned on by someone bleeding the brakes.

--DD

[jimbeaux911]

Thanks Dave! great feedback. So as soon as I install the banjo bolt on the rebuilt calipers I ordered from you guys the flashing might just go away without any further electrical searching!

Very Cool!

Thanks!