e-brake warning light 74 911

[speedo]

Always worked fine as a warning when the e-brake was still on while attempting to drive. Yesterday, it decided not to go off. Thoughts? There is a relay somewhere, but I thought when a relay went bad...it just didn't work. There is no fuse for this, so I either figure it out quick, or remove the bulb in the instrument.

Speedo

[porwolf]

The E-brake warning light has an electronic circuit built in. It also controls the brake fluid pressure in the two circuits, at least in my 79 SC. That circuit sometimes needs to be reset by disconnecting the battery ground cable for about a minute and reconnecting it.

[DRACO A5OG]

Also the ground may have fallen off at the ebrake. ask me how I know

[speedo]

Is that in the tunnel underneath the e-brake handle, or back by the tunnel cover in the pasenger area...thanks for replying guys

[DRACO A5OG]

Actually it is on top of the tunnel right below the ebrake, it requires it being lifted by removing the bolts, keep the cables connected and trace the brown wire, you will know if it is loose off the ratcheting device.

it helps to remove the seat, peeling back the carpet and heater console.

[Jerome74911S]

Are you talking about this?

[DRACO A5OG]

That would be it



The "L" part, it is connected to that wire

[HarryD]

If your '74 is like my '73, it could be the switch on the MC has failed. Here is my story: Brake Lamp Blinking

You can disconnect the wire from the MC and see if the light goes off. This happened to my car several years ago. The handbrake switch continued to operate properly.

You can replace the switch without needing to drain the brake fluid. You can access the MC via the driver side wheel well.

[ossiblue]

Originally Posted by HarryD

If your '74 is like my '73, it could be the switch on the MC has failed. Here is my story: Brake Lamp Blinking

You can disconnect the wire from the MC and see if the light goes off. This happened to my car several years ago. The handbrake switch continued to operate properly.

You can replace the switch without needing to drain the brake fluid. You can access the MC via the driver side wheel well.

+1

I strongly suspect the MC connection as well. The e-brake connection is a second likely candidate. Follow HarryD's advice as the test is simpler, IMO, than tearing into the e-brake connection.

[speedo]

First I disconnected the wires and the flashing light went out. That told me the Fortunately, I had an extra MC on the shelf so I stole it's switch. Installed it and it works great. Funny though...bench tested the old switch with an ohm-meter and it worked fine Being under there gave me a chance to pull a noisy fuel pump and check it. Bench tested fine...think the noise is being caused by crap in the fuel filter in the tank. Gotta drain the tank to get to that though. So I packaged it all back up and will wait till I can drive the tank low.

Thanks for the help guys...you da best

[ossiblue]

Glad things worked out. Bench testing the MC switch may not show the fault. Remember, this is a ground circuit where the light goes on when the MC switch is closed (has resistance) which it will do when there is no pressure on it--like when it's removed from the MC.

I'd also suggest you watch your fuel pump very carefully, especially if it is old. When the bearings begin to go, they often make noise though they still are able to provide adequate volume and pressure. However, it's a failure waiting to happen so if you're unsure of the age/condition of the pump the noise is especially cautionary.