Just one of the little glitches on the way to getting "Pickle" to be perfect (at least for a few minutes).

So, when the parking brake is up, the dash light is one as it should be. When the brake is off, the light still glows though not quite as brightly. I assume that even when the brake is down, there is still a ground somewhere...a ground (short?) that should not be. I have checked the operation of the switch itself with an ohm meter and the switch seems to be fine. With the switch removed, the light still lights up pretty brightly, but if you ground the end of the wire to the body it glows more strongly. Again,this enforces my suspicion that the switch is not the problem. Other than the wire itself grounding somewhere or being shorted, where else could the problem be? BTW, when I first got the switch working last year, the light would go out once in awhile if I repeatedly dropped the brake handle, or took a corner very hard!

Is your's the kind that flashes? If so, it might be in the 4-pronged 914 singal flasher. I've seen that before.

Other than that, make 1000000000% sure the e-brake handle is lined up with the little pin-switch thingy.

If all that fails, feel free to give your 914 to me and I'll deal with it.

What year is it? The later models have the switch running thru the seatbelt relay. Maybe take a look at that?

It never has flashed...not sure if it's supposed to, but I changed out my signal flasher last year when it was the culprit in a few electrical glitches documented on this site. So I doubt it's the flasher relay. The car is a 1970 so I'm sure somebody can chime in as to whether it's supposed to flash. Lining up the e-brake is not the problem...doesn't turn off even if I use my very aligned finger!

I'll give you my 914 if you'll give me $15,000 worth of dimes.

1970

My schematic shows 3 possible items turning on that lamp:
1) Parking brake switch
2) Brake warning switch
3) connection from seat belt warning lamp

There is a diode in place on a brown/white wire from the lamp. This wire isolates the parking brake and seat belt warning lamp from the brake warning switch. The diode allows electrical current to flow only one direction. If this diode is bad, it could cause your problem. The schematic further shows 2 wires (brown/white) connecting to a single pin on the lamp. the first wire is 1 & 3 above. the other is 2 above. I would suggest disconnecting one of them from the lamp to further isolate the cause. If the diode is good, the problem could be the seat belt control located under the passenger seat. The problem could also be the brake warning switch. It sounds like you have a "High Resistive Short". This term is given to a ground switch connection the does not fully break contact. Corrosion, carbon build up and worn insulation can all cause this problem.

Pretty sure that a 1970 has no seat belt warning lamp so we can eliminate that variable. Not sure where the brake warning switch is (on the master cylinder?). On a schematic for 1970 it does not show any seat belt warning lamp or switches. So, what purpose is the diode serving? Once I figure out where the brake warning switch is, I'll check out that connection.

Since my parking brake switch is working, and the chance of that wire actually shorting is minimal, here's my primary theory...lemme know if it makes sense:

The brake warning switch is where the problem is and is staying open to some degree (maybe corroded, dirty, etc.) When the parking brake is engaged, it closes the circuit and it stays brightly lit. When the parking brake is released, it closes that side of the warning light circuit, and the dash light is being kept lit (not fully bright) by a bad connection on the brake warning switch. Make sense?

Could be as simple as broken insulation on the wire. It runs behind the drivers seat then into the tunnel and all the way to the front. Follow the wire and make sure it's not broken along the way ...

Andy

Disconnect the wire from the switch. If the gauge goes dark, the switch is the problem. If the gauge stays lit (dim), the grounding is happening elsewhere ...

Andy

Yeah...the gauge stays lit (dimly) even with the switch removed...it's not the switch. Is the brake warning switch on the master cylinder? I'm guessing it's that switch first. If not there, I'll chase the wire from the parking brake switch.

There should only be one wire going to the MC. Disconnect that and see if there's a difference.

Btw. the MC 'switch' is a push-button that resets the MC warning. It's not the part the wire on the MC goes to.

Andy

Ken - I just looked up your VIN for MY, then saw this!

The early E-brake levers were notorious for this problem, due to the double-action to pull-up & release to drop the "limp" handle to the floor to stow it while the E-brake is engaged. Much of the problem was in the alignment of the warning switch - since you couldn't tell if the e-brake was engaged or not with it dropped to the floor.

Often repeated engagement/dis-engagement of the E-brake lever will get it to cancel. Try to be be very careful & deliberate with the operation of the e-brake handle, firm but gentle (where have you heard that before!? ) & straight up-n-down with the motion - avoiding any slight side pressure which can mis-align the switch/pin/etc. in the handle.

Also try checking the alignment tricks noted above for the switch/pin/etc.

A gal buddy with an early 914 like yours had this problem on hers all the time, which drove us crazy all the time! That was partly why VW-Porsche went to the simpler up or down E-brake handle in later years.

Yeah...think I remember looking for that button when I was having brake light problems. Pretty sure it wasn't there. I probably have the 19mm 911 MC to go with my 911 brakes?

I know that can be a problem, but when I'm using my finger on the switch it should eliminate that concern. 99.9% convinced at this point that it's not the switch, but great info. BTW, what is "MY" in your first sentence?

Model year!?
Tom

You're kidding, right?

Have you tried disconnecting the MC switch? The MC and eBrake are the only 2 connections to this light and it should stay on continuously when either is closed.

Jerry...one of my electrical gurus! I'm gonna unplug it tomorrow and see what happens. I'm betting it's that switch or at least the connection. I'll post the result. Thanks!

Looking at the schematic for "up to 1971" in my Haynes book, there is no MC switch going to the indicator. The schematic for 1972 does show and detail the MC switch and there are several wires on the warning bulb including the diode someone mentioned.

So if you remove the gauge from the dash, there should be only one wire on each terminal of the bulb.

I checked my 71 and it does have 2 wires connected to the brake warning lamp. One goes to the other dash lights (assumed to be positive) and the 2 on the other terminal go to the brake switches.

I disconnected the brown wire going to the switches and measured resistance to ground. With the ebrake pulled, I got a few 10's of ohms which is expected with a closed switch.

When I pushed the ebrake switch in, the resistance when to infinity (open circuit) as expected.

So with your car, try disconnecting the MC brake connector. If that doesn't work, leave both switches disconnected and pull the gauge, pull the wires going to the switches and measure resistance to ground. Somewhere in there you should read infinite resistance and be able to pinpoint your issue.

"Up to 71 USA" shows two wires goung to that bulb (besides the diode)...the parking brake switch and the "brake warning switch". I assume that's the one off of the MC. No?

Thanks...makes sense...will do.

Unhooked the two wires (was only expecting one) on my MC (no reset button found), and the problem went away. So...why is this switch sending a signal (brakes work fine)? Bad switch...grounded wiring...anything else? Should I care?