E30 Zone

Hi everyone

My friend has a 86 sport which we have just finished putting back together. The car has been running fine up until now. When the ignition is switched off and the key is removed the red light on the dash for the battery comes on. When the engine is running it goes off.

Is this the alternator or earth doing it? Or something else?

Thanks for your help

does the car still start fine after not using it for a week?

My light stays on for a few seconds after starting the engine the goes out. If i dont use my car for 5-7 days the battery is flat.

The car did not start after 3 days with the light on. So I swapped the battery just to check it was not that. It started fine with the other batt. I will go start it tonight and see what happens (been stood for 2 days)

The light goes out the moment the engine is running with no delay

Thank s for your help

I had the same problem, I bought one of these off ebay
http://cgi.ebay.co.uk/BATTERY-CUT-OFF-S ... dZViewItem

and then one of these:
http://cgi.ebay.co.uk/12v-Solar-Panel-P ... dZViewItem

First item allows me to disconnect battery from everything (with the addition of a second wire alarm and SI board and stereo can all stay connected). Second item trickle chages battery when not in use. Though if I don't start her for about a month and go for a long drive in 3rd gear it still goes flat too flat to start and requires a quick charge from a proper charger, I think its a combination of the small current drain and cold weather at the moment.

The charger must be hardwired onto battery and not the lighter socket (since the first item disconnects it!)

Thanks

I will look into the cut off switch. the car is only left standing for 3-4 days at any one time. The si board is the only thing that will need power. Thank you

the cut off switch looks like a good idea.

Instead of bodging it with unnecessary aftermarket stuff, how about fixing it properly?
I suspect there's a faulty diode or two in the alternator.
Remove the blue wire from the alternator with the car stopped. Light should go off.
Earth the blue wire. Light should stay off.

Thanks super Brian

I was only going to use the cut off as a tempory fix for now.

Again thank you very much