E34 "Hand-brake on" dash warning

[tonic]

Can anyone help?
A few weeks ago the warning appeared on my E34 535i dash - then went away for a week and now it's back and won't turn off.
Extremely annoying when driving! Naturally I tested the hand-brake (parking brake) and it's functioning normally.
I've also taken the handbrake assembly apart. The simple little sensor at the base of the hand-brake appears normal.
Is there anyway to turn off that particular warning? or could the little switch actually be faulty? or can the sensor be by-passed?
Thanks

Tony
Cape Town, South Africa

[whiskychaser]

You could simply cut the wire. Imagine though, you go to the airport to pick up family along with their suitcases. Because of the extra weight, you don't realise you haven't released the handbrake fully. Your rear brakes overheat and cause an airlock in the brake fluid. You arrive at an intersection with the lights on red. You find you have no brakes and sail through it....

Or you could just get out your multimeter and check the wiring diagrams here:
http://www.wedophones.com/BMWManualsLead.htm

It is a simple switch to ground and is probably worn or sticking :-)

BTW. Welcome!

[tonic]

thanks, whiskychaser

Switch appears ok.
I had a look at those wiring diagrams and I also tried cutting the wire.
No change.

[whiskychaser]

That sounds like the line from the cluster is being grounded before it gets to the switch. You can soon check - put your DMM on ohms, put one terminal on ground and the other on the wire back to the cluster. If you get continuity, you have a short. BUT. Are you sure it isn't a low brake fluid warning instead?

[mattyb]

welcome there e34 brother

[genphreak]

The wire runs to the rear power distribution box under the back seat. It may feed the General Module or maybe just the Relay Module, which in turn activates the dash light. The wire to the switch is fragile, perhaps damaged so check. Grounding it should turn out the dash light wherever you should so choose to test doing so. Maybe there's a break in the wire- or the connectors- check under the carpet for corroded connectors- maybe water ingress is the cause as the sunroof drains can clog and leak imperceptibly every time it rains. Or physical damage.

Removing the bulb form the dash is an option too.. but hardly the safe option.

[tonic]

Thanks for the advice....will check the entire length of the wire.
I'm assuming that if the wire is damaged/broken somewhere along its length, but doesn't earth at the break point, then the light will remain on?
(I don't think removing the bulb would help as it's the audible chime which is the really annoying part)