200 tdi - electrical problem

[leigh]

hi, I have a 200 tdi disco, which when I first had had it wouldn't hold a charge over more than a few days. I replaced the battery, but it still wouldn't hold its charge for any length of time, although when used daily was perfectly fine.

I suspected that something was draining the battery, as the electrics are slightly strange - the wipers, radio etc will work even with no keys in the ignition.

I disconnected the radio as this was fitted just before I bought the truck, and also disconnected one of the door locking solenoids - the lock doesn't work but someone suggested the solenoid might still be powering up.

I then jump started it and took it for a run, but there was no charge in the battery when I got home and tried to start it, did the same thing again a few days later, a nice 35 minute run and still nothing. Has the alternator packed up as well?

Any ideas on what to check would be greatly appreciated - I am reasonably mechanically minded, and know a little about electrics (i.e. I don't like or trust the stuff), but don't have much experience with vehicles.

thanks

leigh

[Les Henson]

The easiest way to see if the alternator is working is get the engine running and then disconnect the earth terminal of the battery. As the alternator takes over from the battery once the engine is running - the engine should continue to do so with no battery. If the engine cuts out, then the alternator isn't charging or there's a problem with the wiring. Getting the alternator checked isn't generally very expensive. I pay £1.50 if the alternator is off the vehicle, and £5 if it's still on it.

Les.

[Comical Engineer]

Easier still:

Voltage of battery with engine switched off approx 12-12.5V

Voltage with engine running & alternator charging = 13-13.5V

If everything operates with the key removed, you have a wiring problem. Wipers, radio etc should not work with key removed. Headlamps will work but have warning buzzer and windows will work for a minute or two after trning the engine off, then stop. Interior light will stay on for 30s after doors closed.

[LandyManLuke]

I'd go with checking the battery voltage first too.

An alternator won't thank you if there's a wiring fault and it's run open circuit.

[lrfarmer]

i replaced my alternator on my 90 as it was draining the battery,

I'd go with checking the battery voltage first as if the alternator isn't working that will tell you.

dose sound like you may have a folt in the electrics. so if the alternator is working fine theres a drain somewear under the dash.

[leigh]

Thanks for the advice, will borrow a multimeter from work tommorrow and have a look see. Supposed to be packing to move house, but her majesty is working late...