Power Drain Issues

[Andrew Bell]

I've had the car (97 Cabriolet) off the road for a few months as it needed a few bits and pieces doing. Knowing it was going to be sat I removed the battery and kept it dry stored and hooked up to a trickle charge with protector, diagnostics, etc. It was an almost new Yuasa so I expect it to be fine and the indicator shows it's all good.

Last night I dropped it back in the car, turned the key and apart from all the dashboard lights coming on, nothing happened. Not even an attempt at a crank. I put the charger on, left it overnight expecting it to be fine this morning. What I didn't do was disconnect it from the car...

Now, the battery seems to have less voltage than it did yesterday, which leads me to believe something is draining the battery whilst the car is parked. I'd suspected this before it came off the road too... As part of what I was doing I'd already disconnected the stereo and powered seats, so I know it's not those. My guess is the aftermarket Cobra alarm (an old version of their "basic" alarm) - what I don't know is where the module is, where it's likely to be connected or how to go about disconnecting it.

Can anyone point me to places it might be hidden?

Thanks

[Steve Q]

My bet would be the alarm too. The only way to find it would be to trave the wires from the fusebox. This should be obvious as they'll look different to the rest of the stock loom. 

Unfortunately these aftermarket alarms can be a problem. If you get a chance watch the old top gear challenge with the 3 series convertibles. Hamonds one had a similar problem.