Car is a '96 Formula. The bolt that connects the red power line to the back of the alternator keeps backing out. Of course when this happens no chargee. Is it safe to use thread locker on the bolt, or this there another fix?

 

Can't remember.... is there enough thread to double-nut it?

Or is the stud backing out of the alternator?

 

The stud appears to be all thread with a nut. I might be able to get another nut on it. Was wondering if thread locker would interfere with conductivity.

 

Yes. The eyelet on the wire produces maximum contact with the sides of the nut. If you insulate the nut from the stud, it would seem that significant conductivity could be lost. They make "thin" jam nuts, so that might help if there is only a couple threads available. Or two thin nuts?????

 

A lock washer might work.

It's not the nut coming loose from the bolt. The bolt itself comes loose from the alternator. Unscrews itself in some fashion.

 

Use a prevailing torque nut (e.g. aircraft nut). One with a plastic insert or swaged edge.

Google it. You'll see examples.

 

Threadlock would be ok there. And/or a lock washer. But the stud or alternator may be stripped or worn too badly to stay put. Can you tighten the stud to the recommended tightness (about 10 lb-ft)?

Another possibility is that the cable is too tight and pulls on the stud, turning it with vibration.

Now that I read again... "all thread with a nut". Does that mean there is no shoulder between the nut and the alternator? You may have the wrong stud there.

 

I misread, earlier. You need to open up the alternator and secure or replace the stud.