Strange electrical fault, please help....

[andrew2986]

Hi All,
Car is a 97 3.9V8 Disco.

Recent History.
Have just changed the starter motor, I disconnected the batteries whilst I did this, due to other events I left them disconnected for three days.
When I leave the Disco for long periods I always disconnect the batteries for months at a time and have had no ill effects.

Fault.
The electric windows, central locking do not work.
Hazards don't work (but indicators do)
Horn doesn't work
The interior light, radio, CB (cb is wired to interior light circuit) doesn't work
If any of the above i.e. interior light does work its like it shorts out or pulls down the electrical system.
For instance if the radio does come on, if you turn on the interior light the radio goes off and then nothing works for a few minuets.
The alarm keeps immobilising the engine, i have taken out the appropriate fuses to disable the alarm in the mean time...
The engine starts and runs fine, lights work, car drives perfectly. All instruments work.
Problem seems to be locking,windows, alarm, horn, hazards interior light related....

I have tried a jump lead from the neg to the engine incase its earth related, my feeling is there is an earth fault somewhere but I have no idea where..

Any thoughts please help as I need to get this sorted ASAP

Cheers guys

Andy

[piggysteve]

Andy, have you checked the fusebox for damage/burning smell

Steve

[andrew2986]

Hi Steve,
Yes !
I think its something to do with the Multi Function Unit behind the fuse box.
all the problems are to do with satellite 2 fuses : windows, locking, interior lights....

[piggysteve]

We had similar once but it was only lights, our Chris rewired the thing to get us going

[MADBEAR]

I had a similar problem with a vauxhall frontera it was water getting in threw aril into the interior light.

[andrew2986]

Thanks for all your replies


Its all fixed!!

Once I had my copy of the Rave wiring diagrams rather than the Haynes crayon drawings it was easier to see what was what.
Turns out that the main loom had been damaged near the under bonnet fuse box. Some of the wires had a small nick in them. The only thing I can think of is I must have nicked the wires when I was patching the inner wing. I did this THREE years ago !!! the nick in the wires had slowly sulphated (?) as there was a bluish coating to the wires some of which had been eaten all the way through ( total of 6 broken wires !!).
To be honest Im surprised the any of the electrics worked at all.
I had been out in the Disco the other day and had gone through a few fords, some off them were quite deep (above headlamps) so all that water must have been the final straw for the loom.
So all soldered up and heat shrinked now and as good as new.

Andy

[piggysteve]

Glad you've got it sorted Andy