Charging issue

[Shankster]

I have a 1990 m925a2 and it will not charge. All I get is 24.3 no matter what I do. Batteries are new and the generator has ben replaced at some point. The other day it did this and if I grounded the mounting bolts to the generator it woud charge and I thought I found the problem with the battery cables going thru the floor but I guess not. Any help greatly appreciated

 

[NDT]

First thing to check is if the small wire at the alternator is getting excite voltage when the ignition is turned on.

 

[Shankster]

First thing to check is if the small wire at the alternator is getting excite voltage when the ignition is turned on.

It was showing 12volts

 

[NDT]

Well there’s your problem, needs to be 24 volts.

 

[Shankster]

Well there’s your problem, needs to be 24 volts.

Just rechecked it and it does have 24 volts

 

[NDT]

If the alternator is properly grounded, and the little excite wire has 24 volts going to it with the ignition on, and the heavy gauge wire has 24 volts as well, the alternator needs overhaul or replacement.