Hand Brake Warning Light

[Ian France]

Hi from France where understandably (or rather not very understandably when it comes to technical terms ) everyone speaks French.
My 1983 911 SC Handbrake warning light is on permanently
Tried to adjust it but no change - Thought maybe it was the contact so got the old contact out to fix /replace (it looks fine to me ) then noticed that even with the old contact in my hands the warning light still stayed on!
The French manual says (as far as I can translate ) that if the warning light comes on when braking it --"could mean one of the two braking circuits may not be working" -- the brakes work fine and the light is on permanently not just when braking but...
Is this light connected to the main braking system in some way I thought it was just the handbrake ? how can it still be on when im looking at the contact in my hands?
Any thoughts greatly appreciated
Thanks
Ian

[RWebb]

how is the brake fluid level?

[Mitch Leland]

It might not be your E-brake at all that is leaving your dash light on. If you have your brake pad wiring hooked up it could mean worn brake pads. As mention earlier there is a float switch in your brake reservoir. Remove the reservoir cap and make sure the plunger is free. Just the other day my dash light was on, I removed the cap and found the plunger was stuck. Just a gentle push on the rod freed up the plunger and all is well. Naturally we're assuming that your reservoir is properly filled...

[James Brown]

I hate those dual function lights, suspect the worst, hope for the best. Jump the parking brake switch and see if the light is still on. If it is, then dive into the brake system. Do that right away, that light might save your life.

[TibetanT]

BTW:1983 911SC does not have brake pad sensors.

Here is what I did to fix this problem on my car.

Try turning the key to the "ON" position, then unhook the positive cable from the battery. Replace the cable, turn the key to the "OFF" position and then start the car. This usually fixs the problem. Light should go out.

If not, the sensor switch is bad on the hand brake.

Bonjour, Mon Ami.

[Ian France]

Thanks guys
Really appreciate the response -was beginning to get paranoid about the brakes -and my French -
--Checked the brake fluid and was ok (no float switch though - think thats maybe a US version addition -)
Light stayed on with the Hanbrake and contact completely isolated but re assembled and tried Mr Ts battery thing this morning -some weird noises when reconnected but when started the engine and released the handbrake (or as I now know " Frein de blocage" in French ) -- no more warning light !
Small village in Provence Countryside for lunch - love those windy roads --
Merci a tous
Ian

[KNS]

I don't believe the '83 had the float sensor in the reservoir.

[MikeRick]

I know this post is a little old, so I hope someone will still reply.

Recently purchased a 1978 911SC. It is my first Porsche and will be mine for many years to come. My only issue, in the week I have owned the car, is the handbrake. When disengaged, it seems to need to click into place. This is not always easy to do. It needs to be pushed down and slightly to the right to get the light to turn off. Sometimes it will click into place, other times it's a frustrating fight. I'm not even sure if this is something that is supposed to happen, (clicking into place), or I have just managed to find a way to get the light to turn off. Any help is greatly appreciated.

[Mrmerlin]

take a look at the switch it may be bent and your bending the handle to touch the switch

[James Brown]

The switch is a mechanical thing, make sure it's not a brake thing! they share the same light!!

[RWebb]

pull the rear wheels off and inspect for crud/adjust

BTW - what did the PPI tell you when you bought the car?

[86 911 Targa]

Ian,

It's been a long time, but I had a very similar issue with our '86.

The light stayed on solid. No flashing.

It turned out to be the Oil Pressure Switch Sensor located near the
oil thermostat.

The switch broke externally, and was leaking oil.

Without a CKT diagram of the warning light indicator circuitry,
I have no idea as to the relationship between the sensor,
and the brake light.

Here's a jpg.

Bon Chance,

Gerry

[Jdub]

In my '78 there are two reasons why this light stays on:

= The mechanical switch at the emergency brake is midadjusted

= There is a disparity of pressure between the two master cylinder switches

If futzing with the emergency brake handle seems to flicker the light suspect the mechanical switch. Otherwise, ask a friend to watch for your brake lights and press the pedal - do the brake lights come on at an unacceptable pedal depression? Or at all?

[HarryD]

Originally Posted by Jdub

In my '78 there are two reasons why this light stays on:

= The mechanical switch at the emergency brake is midadjusted

= There is a disparity of pressure between the two master cylinder switches

If futzing with the emergency brake handle seems to flicker the light suspect the mechanical switch. Otherwise, ask a friend to watch for your brake lights and press the pedal - do the brake lights come on at an unacceptable pedal depression? Or at all?

Another possibility is a failed switch in the master cylinder.

I had my brake light start blinking.

I checked the handbrake and it was operating properly and the switch was functioning as designed.

I checked my brakes and all was normal. Pedal effort and stopping distances were as expected.

I reviewed my wiring diagram and found that the circuit for my brake light went like this:

Power --> flasher --> light on dash --> switch on master cylinder --> Switch on Hand brake. Both the switch on the master cylinder and handbrake would go to ground if activated (i.e. the switch is normally open).

I pulled the wire off the master cylinder (it also acts as a jumper to the handbrake switch so it remained functioning) and my light stopped flashing. If I pulled up the handbrake, the light came on, as expected.

Once I replaced the switch on my master cylinder, the flashing was stopped.

[Mothy]

OK - to add to the complexity of these little suckers. In my 83SC the light comes on:

• if the engine oil level is too low and the gauge on the dash shows low
• if the hand brakeis applied

If the oil level is high the light only glows very dim until I pull on the handbrake.
If I pull on the handbrake, the oil level gauge jumps up about a quarter of its range.

I suspect I have an earth issue combined with a few other malfunctioning bits. Pressure switches all checked out fine.

[HarryD]

Mothy,

You have some type of low level short. Check the wiring diagram and take some time to isolate the source:

[RWebb]

Originally Posted by MikeRick

... the handbrake...seems to need to click into place. This is not always easy to do. It needs to be pushed down and slightly to the right to get the light to turn off. Sometimes it will click into place, other times it's a frustrating fight. ...

- note that this thread was revived and the revival is for a mechanical problem

(tho the elec. replies will help other viewers...)

[sabeo.m]

My e-brake light was staying on... turned out to be my brake housing's, the few things i have not replaced yet. Any how, my rear light's were working but, because my housing are so old, i guess every time i would hit a bump in the road, one of my tail light bulbs would get loose causing the warning light to stay on when i would restart the car. First I pulled the negative off the battery, I pulled the brake lens covers off, cleaned bulb terminals, pulled copper bulb terminals out a little with a flat head screw driver to add some tension against the bulb. Reattached the negative to the battery, started her up and put the e-brake down, the light went out as it should-with all rear lights working as well. replacing those housing are on my project list, they are expensive $$$! I thought at one point it was the switches on the master cylinder, luckily for me those switches are still functioning.

[MikeRick]

Thank you for all of the replies. What happens, is the the handbrake will go down and the light will go off. The handle will then pop back up, (maybe a 1/4 inch or so), and the light comes back on. It seems to me, to be more of a mechanical/adjustment problem. I am usually the type of guy to just tearing things apart, but this isn't a '72 GMC pickup.

[RWebb]

Originally Posted by previous posters

pull the rear wheels off and inspect for crud/adjust

BTW - what did the PPI tell you when you bought the car?

take a look at the switch it may be bent and your bending the handle to touch the switch

- what results when you did the above????