My brake warning light is on. I rebuilt the front calipers to fix leaks, then flushed and bled the system. I have good brake pedal and the car stops just fine. The brake warning light is still on.

I looked for the reset on the warning switch, but could not find one. Instead I pulled the switch from the master cyclinder expecting to find something to reset in there. The switch is just a plastic plunger. the connection is closed when the plunger is fully extended, open when the plunger is depressed. I pushed it, tested it, and then reinstalled. I still have a brake warning light.

Should the plunger remain depressed when I push it? Is there something wrong with my master cylinder? Is there something else I need to do on the master cylinder to reset this? How is the warning switch supposed to work?

Thanks,

Mike

The reset switch is part of the MC itself. You were looking at the brake light switch at the pedals, which has nothing to do with the reset.

You need to get under the car to reset the MC. You might be able to get to it through the drivers side wheel-well ...
Andy

I don't know firsthand about the reset switch, mine last time didn't need to be reset. All i can suggest here is to make sure the ebrake handle is down all the way. Hopefully someone who has first hand knowledge will chime in.

I pulled the switch off the master cylinder. I read that some have a reset switch, but some don't. Mine doesn't have a reset switch on the outside.

The switch is threaded into the side of the master cylinder. It has a single brown wire. When I disconnect the wire, the warning light stops blinking.

I've never seen a MC without the switch on it (at least for a 914). Granted, I am working from a small data set (3) but I thought they all had them.

So, you pulled the brown wire and are still having the brake light on?

Zach

The switch on the MC is a push style button, usually under a small rubber cover.

There's nothing to "pull" ...
Andy

Here is a picture of my MC with the switch installed. There's a plastic blade on the switch, but no reset button. No other button that I can find on the MC.
Click to view attachment

This is the switch. Again, there doesn't appear to be a reset. There is a plastic blade next to the spade connector, but it doesn't move when pressed. Switch is closed with the white plunger extended, open when the plunger is pressed.
Click to view attachment

have you checked the button switch that is beneath the parking brake lever? you have to remove the driver seat, take a good look beneath the lever and see if something is not permitting that little button to release. This is the only other electrical part of the brake like warning circuit that would cause the red lite to flash. It might the spring that the switch block itself is cracked and the circuit remains closed.

I will check it, but I don't think that's the problem. When I disconnect the switch at the MC the light goes off. Would't the light stay on if the parking brake switch were the problem?

Uhhhhhhhhhhhhh, Andy? Did you even read his post? He said he did that in the second paragraph.

The Cap'n

interesting... mine doesn't have the plastic blade, just a push button where the plastic blade is at. Is the plastic blade removeable? It kind of looks like the button is under the plastic blade. Everytime I bleed my brakes i have to push this button to get the light to go out.

Was the light out before you started messing with the brakes? If not, then it could be a wiring problem. The wire that plugs into the switch should be brown with a yellow stripe, I believe, and not just brown. If it's plain brown, look for the actual signal wire somewhere in the area and see if it has shorted itself to ground somewhere...

--DD

I seem to remember George saying something about if it is not on the outside, there is a re-set on the MC side.