Battery drain, E30

[Palazzo 477]

My dad has my old M325i, about 18 months ago, it drained the battery and killed it.

New battery installed, started going south also, when I was there (it's in Wellington) in January, it would struggle to start the day after being driven, unless it had been for a long drive, in which case it would last 2 days. Now that has been pronounced dead after 15 months.

It has never had an issue with this in the previous 9 years we owned it and only two things have changed since he's had it.

Rust in roof was repaired and check control panel/lights were disconnected. A new electric aerial was fitted. This coincides with the start of the drain, but a sparky yesterday declared no drain.

When the new battery was installed a continuous ticking sound was heard, which dad thought was the cd stacker, but I'm thinking the aerial? There is a slim grey box under the parcel shelf with a cable held in by a knurled steel knob, aerial connection and booster?? When this was undone, the ticking stopped.

Am I on the right track, or does someone have another bright idea?

Cheers.

[hotwire 352]

Unless it is a random, intermittent current draw then it should be easy for an Auto Sparky to diagnose/confirm.

Seems strange to me they cant. You need to discuss your thoughts with them - tis nigh on impossible to diagnose over the net. No there should not be continuous ticking though.

Current draw will flatten a battery but not "kill" it, unless its old & past it.

[Palazzo 477]

First battery was old, second one wasn't.

Same sparky that said battery was dead couldn't identify any drain. I know I'm chasing rainbows over the net, but I'm sure it has to be something simple and most likely something related to the aerial, too much coincidence otherwise.

Cheers.

[hotwire 352]

Get them to recheck it & explain what you have said here. Its not rocket science in an E30 to check current draw. That said sometimes things can be intermittent.

Get them to check the aerial circuit - maybe its wired incorrectly, would be a constant drain though. Otherwise a faulty aerial?

[Palazzo 477]

Thanks, I'll try explaining it to dad and see how he goes. I think it's constant draw to drain the battery the way it is. Maybe a faulty aerial too?

[aja540i 1906]

try disconnecting it for a few days and see if that solves it, where in the roof was rust done? if a wire to a courtesy light has had the insulation melted off it might cause an issue.

[*Glenn* 854]

where in the roof was rust done? if a wire to a courtesy light has had the insulation melted off it might cause an issue.

That would cause a short and blow a fuse