Rangie Flat Battery help

[Nikki]

i posted a while ago about my range 1996 P38 2.5dt bmw engine having a flat battery for no apparent reason, we had a diagnostic test run on it on friday, they couldnt find any problem apart from the relay on its way out for the glow plugs. It's been fine for the last week or so, starting up no problem, then last night with the sudden drop of outside temp its dead this morning. Seems to happen whenever the temp drops drastically outside, it has a brand new battery on it, teminals all tightened, earthed properly (old man has checked and done everything), normally pretty good with cars but this one has us all stumped! Short of a box of swan vestas what can we do?! (beleive me its coming pretty close now as this is the next of a list of probs we've had). Can anyone offer any advice please?

 

[discomike]

This one has me stumped, I read your last posting and thought maybe you got it fixed. Wish I could give you some direction, let us know how it goes.
Mike J.

 

[disco1]

Hi Nikki. I haven't read your previous post, so I might be asking you a question that's already been covered. I guess you have leak tested the electricals with the ignition switched on, but have you leak tested the battery with the key turned to accessories? If not, there's a good chance that there is some device that you are not aware of, getting power direct from the battery.

 

[Nikki]

hi disco1, we've had the battery and alternator checked twice, all was ok then, and it's been on the diagnostics test machine at a specialist rover place twice and nothing came up, is that what you mean or do u mean something else? Is there a way that we can test things ourselves or does it have to be done by a specialist? We're now considering getting a trickle charger but the car is left outside on our driveway which could be a problem at night

 

[discomike]

If you are unable to find the problem, you might consider a battery on/off switch to cut the connection from the battery to the truck on those cold nights when the battery would normaly get pulled down.
Mike J.

 

[Nikki]

any ideas what could drain the battery only in colder weather? is there anything that kicks on overnight?

 

[Nikki]

also what exactly is a soak test? how do they perform those?

 

[discomike]

The only thing I can think of is that when it gets really coldeither a switch or relay that is about to fail activates do to the moving of the metals as they get cold thus causing amps to be used during the night.
Mike J.

 

[Nikki]

thanks discomike, they did say last week when it was on the diagnostics machine that the glow plug warning lights fails to light up on the dash, it does it when it feels like it so the man said it could be the relay for the glow plugs on its way out, would that make sense to you? also is it a job that we could do ourselves? where is it located?

 

[discomike]

You pull alot of amps with the glo plugs on and if it is that you will burn out the glo plugs from prolonged excessive heat.
You might want to pull the relay on a couple of nights when it is real cold and see what happens.
mike J.