switch under dash and in glove box ???

[Smokey Boyer]

There is a small silver switch under the back of the dash on the drivers side of my 1991 S3. It is further in to the footwell than the square boot release switch. I can see there are two blue wires running from the switch to the centre console.

There is another identical switch inside the glove box.

I am not sure what either of these do. The previous owner of the car had no idea either. I have switched back and forth with the engine running, and they appear to do nothing.

I think they may have something to do with the Cobra Alarm, that is currently switched off while I try and sort out a replacement and working key fob. Could also be something for the radio, but again they do not appear to change anything.


Any ideas what they might be before I spend hours tracing the wires through the car.

[v8s4me]

Apart from the ECU the wiring on the V8S is similar to the S3 and there’s nothing like that on mine. They could be to do with the alarm but they could be there for lots of other reasons as well. If switching them on and off doesn’t do anything then I’m afraid you have little option but to follow the wires and see where they go.

[kevroe]

I used to have a hidden switch like this one my old escort. It was to disable the ignition by shorting out the power to the distributor. It was a simple way of stopping someone driving off with your car. However if flicking your doesn't do anything I guess it's not that! Follow those wires!

[phillpot]

A switch hidden away in the glovebox does sound like a "secret immobiliser" switch, cutting ignition or fuel pump feed maybe?

Could the other be a fan over-ride switch to manually switch cooling fan on?


Or it could be.........

[Smokey Boyer]

After a bit of wire following, trial and error, I have found out what the two switches do.

The switch under the dash, above the drivers right knee, was intended to be a control switch for the electric aerial, but was not wired in correctly. Having sorted that, it now provides a control over the aerial so that you can listen to CDs and tapes without having the aerial up. I know, why would you want music on in a car like that.

The switch in the glove box, was wired in to the alarm at some point, but one of the wires had snapped through. I assume it allows the vibration sensor to be turned off given that it is wired in to a box with a ball rolling around in it. Just need to get a cobra key fob now.

[Barkychoc]

The ball in a box is a shock sensor, pretty much what you said.