Electrical issue
Turbo Mini Forums

Recently had a few weird issues with electrics.

1. sometimes battery seems to flatten overnight.
2. Had to have my ecu repaired due to 2 injectors diodes failing at the same time.
3. Once engine kept running with ignition key off, had to disconnect power feed to ecu relay.
4. Had to have a new brand new Bosch battery.

Now

The ecu keeps the engine running after ignition key us turned off 90% of the time. At key off there is still 2volt showing at ignition live (white wire) which keeps the power relay energised. If I disconnect the feed the engine stops and fusebox shows 0volt. I've replaced the relay for a different style as it does the same thing.

On investigation, I've found if a disconnect the alternator connector everything seems fine, apart from battery not charging obviously. Also my amplifier then works again (12v remote feed, comes back from head unit). This leads me to think alternator fault, however it charges fine at 14.4v when connected and is pretty new. It's a 85amp from WOSP. But could explain why I fried my ecu.

I've also got a old style wing mounted solenoid that I thought originally may have been at fault. Starter turns fine and as never stuck

Now this a cant explain, whilst looking for battery drain, i noticed with the battery 12v terminal connected and negative post disconnected, I can still measure 1volt at the solenoid on multimeter when multimeter black lead is attached to chassis. This is with alternator connector plugged in or not. Is this normal? It doesn't do it on my red mini.

Edited by alaskanow0 on 22nd Mar, 2013.

Class C 3rd Place Avon 2011 14.18 @101mph

weird,

sounds like it could be the alt back feeding, what alt is it, Denso? can you pull the ign bulb and see if the problem goes away?

the 1 volt residual without the battery connected is strange, could be a capacitor in something leaking back out, could be related to the 2v at the ign switch. only things that would hold a charge would be ECU, radio, and any smoothing caps for coils.

Sounds like classic alternator back feeding. Put a diode in the wire from your alternator to the dash light - brown/yellow wire from memory.

Alternator is a standard lucus type. Never heard of back feeding, but makes sense. I guess normally 2v wouldn't be enough to keep the coil running.

Edited by alaskanow0 on 22nd Mar, 2013.

Class C 3rd Place Avon 2011 14.18 @101mph

We had it in the van. It was backfeeding into the clocks and in turn one of the relays. 9 times out of 10 we had to pull the relay to get it to stop. Had regular flat batteries.

Pm me your address and Ill chuck some diodes in the post.

Thanks Andy, it's really been pissing me off. I was hoping you read the post, I know your clever with electrics.

Class C 3rd Place Avon 2011 14.18 @101mph

I wouldn't say clever, my custom loom has issues... :$