So this morning the mini would not start. It seems to power up and function but no go to the starter. Although the battery is only a month or so old I have it on a charger overnight. I did attempt to jump it but no go. I have not been successful at finding a wire diagram but found the two wire that appear to go done to the starter solenoid and I assume they are the coil power/return. I disconnected and checked across and my fluke reads about 3vdc during the start cycle. Not sure what the coil voltage is but I'm assuming (hate that word) it would be 12vdc.

So the battery is on the overnight charge and I check in the AM and see what I have. Any input to help me troubleshoot and determine if it just a bad starter/solenoid or something else is appreciated.

 

So my diagnoses was incorrect. I removed the starter only to find out it was just fine. It seems to be an issue with the ground on the motor. Battery, Terminals are good, I even recleaned them. If I added a ground back to the battery the starter would turn. Remove the grd and nothing.

Any ideas? Hate to have to take in to mini but that is what its looking like.

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I just went and connect a jumper cable from engine to neg battery and car started and appears to be running fine. Remove the jumper and still runs but wont restart. I notice that battery voltage and had a slow drain with jumper removed. With jumper, voltage at battery about 13.2

Do then car have a gnd strap to the engine. If so, maybe its damaged or in need of attention.

 

There is a ground strap on the top of the right side motor mount. Not sure if that is the only ground. If the ground strap is bad, the charging voltage ought to be out of range as well. With car running and your ground jumper removed, check the voltage between neg. on the battery and any ground point on the engine. Do the same with your ground jumper in place. You should see a difference.

 

Thanks for the tip. I found the strap and one side was loose. I removed it completely to clean both ends. The loose side had some arching. I just did the Timing chain swap a month ago, I must have not tightened it completely. Ugh, that was a hell a stupid tax to pay removing the intake to check out the start solenoid.

Now to figure out were an oil leak is coming from. It appears to be from the front-end side of the oil ban or possibly turbo drain. I have a new pan casket but haven't changed it out yet due to have to move the exhaust out of the way.

Thanks again,
Dave

 

NO-OX-ID is an electrically conductive, corrosion inhibiting grease, works great on sliding contacts, battery and cable terminals. If you are planning on keeping the car for a long time (years) consider getting some, and applying it whenever electrical joints are apart.

 

6 years and change later, and you just saved me from buying a new starter for my 2011 R55 Clubman S. I didn't check the voltage between the terminal and the block, I just used the jumper to connect the neg to the block directly, and my car started. I took off the ground strap, which was loose (I just recently installed a new friction wheel and had removed the engine mount, SMH for not tightening the bolt), cleaned it up, threw a dab of dielectric on the ends, and she starts up great! Thanks again, you never know when a good forum thread will come in handy!