Electrical problems after jumpstarting series 2 Disco

[para325]

I have a 51 plate TD5 & after coming back from a month in Australia I had a flat battery (no surprise there). I jumpstarted it & went out for a long run to charge the battery, so far so good. Came back home & switched it off & the stereo stayed on. Weird I thought as it's not wired to a permanent live. Anyway turned it off & thought perhaps this was why the battery had gone flat. Then noticed that the cigarette lighter was also still live even with the ignition key removed. I disconnected the phone charger & vowed to investigate further when it was light. I then got out & pressed the locking button on the handset. The horn sounded but the car didn't lock. I checked all the doors & tried again, same thing. So basically following the jumpstart I have permanent live feeds that weren't there before & the car won't lock!! Does anyone have any ideas?? I would be extremely grateful, cheers.

[Roger Whittle]

Oooer - that definitely sounds like one for Jon V8. :eek:

Roger.

[TEMPL4R]

A lot of vehicles have a " Body Control Module" BCM, they don't like the surges of jump starting, welding, etc. They control all sorts of functions on the vehicle. Central locking, Alarms/immobilisers, Lights, etc.

JON knows more about the electronics than I ever will, he can explain.

It is best to start the vehicle and leave the leads on, wait for a while until the battery has got a bit of charge and the engine is warm, stop the vehicles and take the leads off. Start the car again and the alternator will sense the battery is low and gradually adjust the rate to maximum. When you take the leads off a running car, the alternator senses a flat battery and suddenly works flat out, that is the surge that damages the electronics. Some people recommend turning all the lights on to "lose" the current surge, I prefer not to as lights are controlled by modules at times and these can blow.

Chris

[ncooper]

Or better still,disconnect the battery before you leave the car for a long time and then trickle charge it before you reconnect it.

I expect Templ4r is,as usual,quite right but you could try disconnecting the fully charged battery,then reconnect and hope the upset module will re boot successfully.

Nick.

[para325]

Many thanks to all for your advice & suggestions, took the car into work with me last night & disconnected the battery then left it trickle charging for 12 hours whilst I endured a hellish night shift. Re-connected the battery in the morning, started up with fingers crossed & 'hey presto!' everything was back to normal!! Once again many thanks & Merry Christmas.

[TEMPL4R]

Looks like Nick is right and it did reset itself. Jon might be able to give us an insight as to what happens if it is a BCM problem.

Water ingress is a big problem on Minis, Peugueots and Rovers. If you have a BCM that needs changing, it needs a recode if it's from a slavage yard or new.

Chris

[ncooper]

Very good news and a Happy Christmas to you too.:)

Nick.