Electric issues
Turbo Mini Forums

I have some electrical issues i am struggling with, not something i enjoy doing or know much about.

The battery on my new mini drains overnight. borrowed a multimeter, the type that clamps over the cable and reads amps. the +ve cable from the battery that goes up the car reads 2.8 amps when nothing is turned on. If i put the clamp on my break pedal it reads 5 amps. does this mean i have a live shorting somewhere/bad earth?

cheers

Liam

If you put the clamp on your brake pedal? If something is draning the battery, what i normally do is start pulling fuses until the amps go down. Then you know what circuit is at fault.

Try disconnecting the stereo

I had this problem with an old mini years ago.. Had to carry a spare battery around incase I got stuck! Never really got to the bottom of it after checking everything, very frustrating!!

I agree with mcalvert39.. Start pulling fuses one at a time, try and eliminate the cause of the drain.

Pulling fuses is a good idea but check the condition of the battery cable too. I had this a few years back and it turned out the cable had a minor short.

That was prob the problem that I had on mine years ago, never considered the cable itself. Well I was only a pup at the time...

You are reading 5A when putting the ammeter around the brake pedal? That should be at the same potential as the rest of the car, i.e the return path. If you went to the fuse box in your house and put an ammeter around the main earth terminal and you saw any amps being drawn then you would have a problem... As you do with your car by the sounds of it.

Sounds like a direct short to the body of your car, as Rob says check your battery cable. Also, with the battery charged, put a voltmeter across the negative terminal and to earth (the minis shell)... If you get a voltage you have a short.

Disregard that last part, was thinking of something else lol

are you sure the altenator is actually charging it?

Should be around 14v with the car on

yep battery reads 14+v when running

I Pulled a few fuse's today and it didn't show any any difference. will try again tomorrow and try relays. Should it take a while for the amps to die down?

No Stereo, so dont have to worry about that. most cables are new, i will try a new earth to see if it makes a difference. the main +ve cable runs internally.

what i didnt understand is why the reading on this cable was 2 amp but say 5amp on the brake pedal

cheers will try this too,

For a start I would not trust a clamp on ammeter on low current 12v. Disconnect your battery main pos cable, set an ammeter to highest current range (usually circa 10A) then make sure everything possible is off, connect your meter between battery terminal and main cable. This gives your idle current draw that should be very low. If not something on the car is consuming power and flattening your battery, so then it us a case of unplugging things to see what us the culprit.

Im with tom on that. The Clamp ones arnt the best. A proper ammeter will tell you exactly what draw is on the battery. Make sure you set it to amps and that the leads are in the correct plugs on the meter. Ive accidentally blown a couple up in the past.
I hope you find it as the only other way you will find out where the problem is, is when it sets on fire.

I tried this previously but using the earth cable. when i do it (with +ve too) the meter jumps to 5 amp straight away but then quickly dies down to nothing. if i repeatedly tap it on the battery terminal it will stay at 5v.

Are you saying that between earth and this terminal you only measure 0.1V? If so, this is your problem as it means they are at the same potential. Either way, an unsheathed connection sat in the footwell is not a good idea.

that maybe your problem

Edited by wng691s clubby on 6th Jan, 2013.

Done now needs redoing lol

Are those fuel lines aswell?

1293 Turbo mini

That is the positive cable from the battery I'm guessing??

Disconnect the connection you have pictured. Bolt the two ends of the cables back together through the lugs but not to the car floor. Insulate it completely... Retry your tests.

The picture shows (to me) that there is some insulating material under the connection, a rubber stop or something but the nylon nut and bolt will create a short. Make sure the connection does not touch the car floor.. Or any other part.

1293 Turbo mini

Ya I can understand that.. But the rubber is pointless unless you use a non conducting nut & bolt i.e completely nylon... Otherwise you may as well bolt it to the floor without the rubber..

those exhaust rubbers dont have the bolt all the way through, its a bit of rubber with a stud on each end...

if that was grounding the car would have burned out by now.

Ah that would make sense..