Need Help - Electrical Short Somewhere?

[jaymanek]

Hi All,

When I open the door, the ignition seems to turn on (fuel pump starts buzzing).
Also the courtesy light no longer goes off when closing the door..

Another side effect is that if I try to shut off the engine with the door open, it wont, but if the door is closed, everything behaves.

The door contact switches are fine themselves but obviously there is a short somewhere!

I disconnected the plugs for the instrument cluster and indicator lever as these are items I have recently replaced but the fault still occurs.

Anyone any ideas?

Thanks

Jay

[Naj ✝︎]

Brake fluid level ?
If full, then you need to check the floats in the resevoir.

Naj

[jaymanek]

Is that a serious suggestion?! I will check though!

[ja17]

Hello Jay,

Yes, Naj is quite serious.

A fault in the wiring design causes this quirk only when the brake fluid level warning light is activated by low fluid or a defective brake fluid level float

[jaymanek]

Well I never, yes my fluid was low, now sorted.... I would never have traced that!

I'm glad I posted now.

[jacovdw]

Simply topping up the brake fluid in the reservoir is only a temporary measure.

To ensure that this never happens again, a small modification to the wiring needs to be done. You need to fit a Silicon diode in the circuit between the fluid level sender and the red light bulb in the central combination instrument.

A current rating of about 1A with the anode (+ side) facing the bulb will do fine and is small enough to be easily hidden.

Remember that the cathode (- side) is marked with a stripe on the diode body. You should be able to obtain such a diode easily from RS components or Maplin in the UK.

A diode designated as 1N4001 would be fine for this application.

[Naj ✝︎]

(More important) you  also need to find out why the fluid was low!!!

Just brake pad wear or a leak 

Naj

[jaymanek]

Thanks all, I think my leak is at the clutch slave, I will keep an eye on it and sort it at the next service.

Thanks for the diode tip, will def do that.

[Naj ✝︎]

  I think my leak is at the clutch slave 

The clutch hydraulic system should have its own separate resevoir.

Naj

[waltklatt]

Depends on the master cylinder for the brakes.
Some of the reserviors had an outlet tube for the clutch master system.
This I know was on the W123 series models later, where they combined the clutch and brake reserviors into one.
Walter