Anybody good with electrics?

[viperharry]

Hi guys (& gals)
I've got an annoying electrical problem with my 1997 GTS (ex silverstone) which I hope that one of you may recognise.
If I leave the car sometimes for 12 hours or so sometimes longer and then come back to it the whole electrical system is dead. The battery is fully charged (12.8V)and there is no cuurent drain at all when the system is down. If I disconnect the battery and reconnect it everything is fine. If I put the optimate charger onto the jump posts even for a few seconds everything is fine. Sometimes if I open the door manually & close it then the system comes back. Presumably something is tripping out and tripping in again. Any bright ideas?
Cheers
Harry
(PS Baz I'm up for the track day depending on the date)

[viper paul]

When did it have a new battery last, often batteries in Vipers test ok but cause weird problems.

For fifty quid I would try a battery first.

However does it have a poor quality alarm, they can cause excessive battery drain.

If you disconnect the battery and reconnect it do you get a spark across the terminals?????

My hunch..............battery.

[viperharry]

Thanks Paul. Like you, the battery was my first thought so I brought a brand new one but the fault persists. The alarm is the stock one so I guess it shouldn't drain any quicker than usual. I've emailed Chuck and he wonders about the relays on the PCM so I'm in the process of looking at those. Hopefully I'll get to the bottom of it. Off to the LeMans claasic in 2 weeks so I need to be right for that!
Cheers
harry

[GreenV8S]

Daft question, you haven't got an intelligent battery isolator fitted have you? You're describing the exact symptoms I get from the Priority Start system on the V8S when the battery is low.

[V1PER]

The Ex Silverstone Vipers did have a battery cut of switch just not sure what type....

[viperharry]

I'm not aware of a battery isolator or cut off switch but I guess anythings possible. Where abouts might it be?
(PS Paul where do you get your batteries from for 50 quid? It was nearer £150 from the Chrysler dealer!)

[viper paul]

US Automotive used to be quite cheap but they were not shipped with acid which was a problem.