Electrical system failure

Hello,

I fitted a new battery to my 1997 disco this morning, all went fine, started engine and ran up ok. Locked the shed up, went to pull away and the engine stopped. After a lot of head-scratching, it seems that when the handbrake is on (with the dash warning light on) the engine will run, all electrics are fine. When the handbrake is released and the light extinguishes, ALL electrics fail, no dash lights and the engine stops.

I can only think that this is an immobiliser problem. Is there something on the immobiliser that shuts the engine off when the handbrake is released? I cant believe that an open circuit on the handbrake warning light wiring could result in a complete shut down of all electrics.

Thanks, Sam.

A bad earth to the engine can mean that the handbrake cable becomes the engines earth. Possibly, it has been like this for a while and has nearly burn't through.
I think this has been raised a few times before so a search might come up with more info.

Agreed, you have a bad earth!

Thanks for the reply guys, where do you think the bad earth could be? I've just been down to the farm and made a new (huge) earth strap from the battery -ve to the chassis and another (huge) earth strap from the battery -ve to the engine block. This has made no difference at all.

Problem remains - All elecs fine until handbrake released and all electrics fail.

Try removing the lid/level sensor on the brake fluid to trigger a warning then release park brake and see what happens?

Also check fuse 14 (10 amp) in facia fusebox.

Ok, I ran a (-ve 12v) from the battery to the handbrake switch, and swung the switch away so it is not effected by the handbrake at all. All electrics are now fine, but I just get the handbrake warning light up constantly. It's a workhorse so this doesn't bother me at all.