3 replies to this topic

[njathind]

Hi there.

Car is a 1998 mini cooper MPI, trying to get some power into the thing after being restored. The trouble is no matter what I try I just cant get any electricity into the system.

The battery is fully charged and showing just over 12 volts, I have been all over the car checking for continuity using the "bleep" setting on my multimeter. If I disconnect the terminals on the battery and put a probe on the posative lead and one on the negative leed I get a result of little to no continuity however if I go and flick some switches on such as the headlights, wipers and hazards then go and test for continuity again I get a bleep confirming there is a circuit being made.

I have removed the front grill and visually checked the connections into the starter motor and from the starter motor to the engine fusebox and they all look ok. However when I put a probe on the posative cable where it enters the engine fusebox and then onto the engine earth strap I get a very weak reading for continuity. It is making a circuit but its not a very good connection.

The thing I am thinking is if there were to be a poor earth then surely I would get some electrical functionality out of the car even if I went to turn on the headlamps and I got a blast from the horn for example. I have a funny feeling the posative lead from the battery to engine bay is at fault here but thats just what I think. I could be way off.

Many thanks in advance, Nat.

P.S Sorry about any grammer or mispellings, really should be in bed once its past midnight.

[Miniowner123]

run a couple of linked up jumper cables from the positive battery terminal to the starter essentially bypassing the main cable, that way that will quickly rule out that fault

so when turning the key do you get ignition lights? alarm and immobiliser turning on and off as it should?

i had lots of similar issues after fitting an mpi engine and loom into my cabriolet, finally sorted it all out and was down to lots of bad connections and earths

[KernowCooper]

Have you tried by passing the wiring to the boot with jump leads?

Remove the battery from the boot, bring round the front of the car and connect the jump lead red + to the input to the solenoid (usually the top large connection) and then the jump lead black to the engine head bolt or a good earth point.

You have now by passed the earth in the boot floor and the main battery cable, now carry out your tests for voltage at the fusebox and if you have voltage there then test the circuits key on wipers/lights and so on.

If you have no voltage at the fuse box then inspect where the main feed is taken of the starter solenoid and check for a good connection there, if you have a good connection there but still no voltage at the fuse box then trace the wiring back looking for any damage and if you have a sharp probe you can check voltage along the loom by carefully opening up the taping or sliding it along.

Follow this all the way to the fuse box and I would check the connections on the fuse box terminals as they can be corroded.

Once you have done those checks it should pin point whee abouts the problem lies

Edited by KernowCooper, 24 April 2013 - 11:41 PM.

[njathind]

Thanks for all of your help guys, turned out despite the battery having a good enough charge it was knackered. Knicked the battery from my MG ZR and it fired up first time, despite it not being turned over for more than three years.

I was a pretty happy chappy