Very strange electrical problem - windows and auto affected

[chev28]

Hi all,

I have just started getting a bizarre electrical problem with my 1998 300tdi discovery auto. Basically, when you start the vehicle, the windows and radio will not work and the auto transmission makes a grinding when you change into D (or any gear).

The vehicle will drive normally (without windows and radio working) but when you stop and want to put it into park, again it grinds the gears.

The way to fix it is to stop the vehicle, turn it off and restart it. Then everything works again. My only concern is that one day, it will not right itself.

Does anyone know what is going on? Is there a dry joint on that circuit board? Why is the auto affected?

Thanks for any advice.

Adam

[Scouse]

Hmm, 44 looks & no replies yet...


I'll suggest that the problems aren't related.

I don't see how the auto itself can make a noise like that as the gears inside don't work like that - unless it's the Park pawl that's causing it somehow.

As for the windows & radio, have you checked is anything else on the Accessory circuit stops too (wipers?). If so, it could be a failing ignition switch.
The Accessory circuit drops out while the engine is cranking (to give the starter motor full power) & then returns once the key is released. Maybe it's not reconnecting the Accessory circuit sometimes. Try wigging the key when the problem happens & see if they start working again.

[chev28]

Thanks for the tip. I'll try the key.

The problems are related as there is no hint of any issues except for the rara (once a month) time that this happens. The auto bit is really strange. It will go into and out of Park but it feels awful doing this. I am confused as to why this happens - is there an electric component in the auto which controls the park shift?

[justinc]

UNLESS your D1 is an import with an electronic controlled engine and auto with transfer case shift lockout etc then no, they are totally removed from any electrical source apart from the park / neutral switch etc.

ALL australian delivered 300Tdi models had no electronic transmissions.


JC

[chev28]

It does have an exchange box but I can't see why it would have anyhting extra wired up. It seems that there is part that needs power to stay out of the way when shifting.

Anyway, if it was the accessories circuit, why would a worn ignition cause this?

[Catmatt]

Try changing the battery.......I know this is a simplistic approach but I recently had a bizzare electrical problem where if I turned the headlights on - the dash would go blank and the engine would stop

I went throughout the wiring loom completely, checked every clip, switch and plug as well as investigated with a Nanocom and still came up nada.

Posted on this forum and a few suggested possible battery fault.....

So at my wits end, I swapped batteries between my 2 Discos and for no logical reason and nor does it make any mechanical or electrical sense....the bloody car has ran perfectly and still does today.

What does my head in though is that the 2nd Disco hasn't missed a beat and the donor battery works fine

Give it a try......Like you, I had nothing to lose!

[superquag]

Thanks for the great chuckle !

The ghost of Sir Joseph Lucas likes you.....

[camel_landy]

Don't forget that strange electrical gremlins in cars of this age can quite often be caused by faulty earth connections... Especially where transmissions have been replaced as the casings form part of the circuit!!

M

[chev28]

I thought I had paid my homage to Lucas back when I had my vintage car. Maybe he's lurking in my garage still.

Oh well, I'll try cleaingin up battery and earth connections to see what happens. It only seems to come on when the weather gets hot.

Thanks for all the replies.

[Ivan]

Weather gets hot, things dry out = bad earth. Weather cool and moist = good earth ?


Ivan