Blinking Parking Brake Light. Options

[PaIsa]

So while I was replacing the speedo cable I took a look at the parking brake switch to find out that there are 2 poles on the switch, but only one cable?? The only cable is routed toward the front of the car. I would guess that the other pole is to be grounded somewhere. But since my brake light is blinking then I guess that my problem is more then just that.

As well, while the car was in the air, I looked at the switch on the MC, and I have a 2 pole switch and was not able to see any reset on it.

So I am back to searching!!

[Spoke]

So while I was replacing the speedo cable I took a look at the parking brake switch to find out that there are 2 poles on the switch, but only one cable?? The only cable is routed toward the front of the car. I would guess that the other pole is to be grounded somewhere. But since my brake light is blinking then I guess that my problem is more then just that.

As well, while the car was in the air, I looked at the switch on the MC, and I have a 2 pole switch and was not able to see any reset on it.

So I am back to searching!!

@PaIsa

You can try disconnecting the wires at the MC warning switch and see if the blinking stops.

[Dave_Darling]

Some master cylinder switches don't have the reset button; most do. The ones that don't are supposed to reset themselves when the pressure balance is no longer there.

There are switches with one wire connection, and ones with two. I believe that the two-pole ones are the original style.

The two-pole ones work by shorting the two poles together. One wire is ground, the other goes to the warning light. So the switch shorts the wire from the light to ground.

The one-pole switch grounds through its threads. So only the wire to the light needs to be plugged in.

--DD

[Lucky9146]

Some master cylinder switches don't have the reset button; most do. The ones that don't are supposed to reset themselves when the pressure balance is no longer there.

There are switches with one wire connection, and ones with two. I believe that the two-pole ones are the original style.

The two-pole ones work by shorting the two poles together. One wire is ground, the other goes to the warning light. So the switch shorts the wire from the light to ground.

The one-pole switch grounds through its threads. So only the wire to the light needs to be plugged in.

--DD

That was very helpful. I will look at that next time the car is in the air.
Thanks
(IMG:style_emoticons/default/driving.gif) (IMG:style_emoticons/default/white914.jpg)

[PaIsa]

I guess that if the blinking stops then my problem is either a bad switch on the MC or a bad MC that causes the switch to activate.

For the switch on the parking brake, here is a picture of what I currently have on the car. 2 pole switch with only one wire going back toward the dash through the tunnel. I guess that the oter pole is to be grounded, right??

[zman914]

Some master cylinder switches don't have the reset button; most do. The ones that don't are supposed to reset themselves when the pressure balance is no longer there.

There are switches with one wire connection, and ones with two. I believe that the two-pole ones are the original style.

The two-pole ones work by shorting the two poles together. One wire is ground, the other goes to the warning light. So the switch shorts the wire from the light to ground.

The one-pole switch grounds through its threads. So only the wire to the light needs to be plugged in.

--DD

I have that same problem, blinking lights after I changed my master cylinder. I have 2 poles on the switch . Tried everything! Also I have a weird short or something, when I turn my blinker on with the car ignition off, it will turn on my fuel pump!! Has anybody heard of that?? Strangest thing.. Any advice!!

[Superhawk996]

For the two posts above:

Each of you have electrical issues that need to be resolved with a DMM and basic electrical troubleshooting. If you don’t already have a DMM, buy one and learn to use it. These 50 year old cars have been abused and modified by DAPOs for decades. Even just plain old wear and tear takes its toll over time.

Here is a link to a classics thread that may be of some use if not familiar with basic electrical troubleshooting.

http://www.914world.com/bbs2/index.php?showtopic=53850

[burlybryan]

Just to add a some anecdotal experience from a similar issue. The light plus click is usually the MC switch. I had to replace my switch to make that go away.

I had an additional issue where my cars parking brake relay would click non-stop. The light flashed as normal when the parking brake was engaged, but the clicking remained when disengaged. I checked all the grounds in the cabin and what I eventually discovered was a weak front turn signal bulb contact. The clicking was an indication of a poor ground or poor electrical contact "somewhere" - you just have to go on the easter egg hunt to find it.