Alternator Help
 

I'm desparetly trying to get my race car finished and have run into a problem. I have a 901 alternator shroud/housing with a Bosch 0 120 400 725 alternator which is only putitng out 12v. It has never run in the car before.

So, I'm looking to replace the alternator and have a few questions.

Does this alternator have an external voltage regulator?
If so, there is not one installed. So would adding one solve my problem?

If I upgrade to a later alternator which one would be best?

TIA, John

Does your alternator have a terminal on the back labeled "DF?"

And what is the EXACT casting number on your fan housing?

Housing # 901 106 10105R
Alternator terminals
B+ B+
D-
DF
D+

Ok, now we are making progress.

You have a late 901 fan housing, probably off a 2,7, and an externally regulated Bosch Alternator. You say there's no external VR installed, which is why your alternator isn't putting out any voltage. So you should buy a Bosch external regulator from our host here and install it, hook everything up correctly and you should get 14V output voltage from the alternator.

I would not waste time looking for a later alternator as they are heavier, require the use of a different fan housing and they have internal VRs, which are exposed to engine heat, which isn't good for them. I would stick with what you have and get the Bosch VR and hook it up correctly.

Thanks for your help John.
How does it get wired and where should I put it? It is a full race car so there is no wiring except the red, blue and ground goung to the alternator.

John

If it were me, I would put it on the parcel shelf inside the car where you would mount speakers.

http://forums.pelicanparts.com/showthread.php?s=&threadid=253864&highlight=harnes s

It goes without saying that you should use aviation-grade wires, a minimum of 16 AWG, and make sure you insulate everything and route all wires where they will not chafe or short out. If you make a mistake you could very easily burn the car to the ground, so be careful.