I have a 2006 mini cooper s. One day battery ran dead so i went and got it charged at autozone and it was diagnosed as a good battery. Battery is only about 4 months old. So i put it back on the car and it dies again. So i figure its the alternator. I remove it and go have it tested at autozone and ots diagnosed as a bad alternator so i purchase a reman from them. Go and put it on and the same thing happens it kills the battery so i think maybe the alternator is defective so i go and have it checked and it is good. I dont know what to do. Any ideas what it could be? ?

 

Are you sure you got the replacement alternator connected properly?

Have you done any other work on the car recently?

Any chance the engine ground (at the right side motor mount) is loose or dirty?

What about the two big battery cables that meet at the starter? If they aren't connected to the same post on the starter, the alternator will not charge the battery.

 

It has had some work done to the starter, and come to think of it i dont remember to positive cable being put back. Are they together when put back? And the is no power to the positive red wire on rhe alternator.

 

There are two big fat cables that meet at the starter. Both are part of the positive battery cable circuit. One comes from the battery, one goes from the starter to the alternator. They should be attached to the same post on the starter. Check they are both connected... And just in case, a reminder - Don't mess with those cables without disconnecting your battery! They can carry a lot of juice!

 

Thank you so much, I appreciate it i was just about to take it to a mechanic to get it checked but now im sure thats the problem thanks to you. I dont remember putting to cables on rhe same post, so I know thats where i messed up. Thank you.

 

This picture (B&W from TIS, color from Pelican (thanks!) It's from their clutch replacement tutorial) that shows the battery cables at the starter the correct way. Hope it's this easy.

 

I'm having trouble with pictures today. Here's another attempt to post the image from TIS

 

Thank you all for the help. It was that, only one cable was connected and the other one was hanging there.

 

Awesome. Glad it's fixed.

It's a classic mini quirk. No one ever goes looking for the second fat cable to attach to the starter...

 

Good job, David! Yes, if any connections are a tad bit loose you will have issues. Same with the grounding strap. Glad it was an easy fix.