1971 RX2 Alternator not connected.
I had a problem where my alternator was not charging the battery. I had this NOS alternator in a box, I took it to the parts store and had it bench tested. It tested good, putting out 14.x volts. I put in on my car, did not connect except the belt so I could check the voltage myself before connecting the wiring. I touched that part with the red arrow with the positive ammeter prong, and touched the ground ammeter prong to where the black arrow shows. I also touched the ground to the case, and the other places. I did not get any voltage! What am I doing wrong? I know the alternator is good, and it is not hooked up yet, so it should be working?

 

check your Voltage regulator

 

The voltage regulator at this point is not connected. I'm just checking the output of the alternator raw. The only thing attached to the alternator is the pully belt.

 

you cant test it without the the 4-pin prong and main wire to B terminal

 

check here

Foxed.ca - Mazda RX-7 Manuals

 

The Main Wire and 4-Pin prong are now connected. (And the belt drive of course). When I test it by touching the ground to the battery and the positive to the main wire, I'm getting nothing. I also tested it by touching both battery terminals, only 12.3 volts, I'm not getting anything out of the alternator. I put a new grounding cable on, I know that is good. I have gone through two new voltage regulators. Any chance both of those are bad? I just don't know what else it could be.

 

while the engine is running Touch the black lead from dvm to ground (alternator case or block) Then touch the red lead from the dvm to b+ ( Main wire ) you should get 13 to 15 volts. Very Important...Have your read the test procedure In the Manual? If not stop everything and read them. if you cant find an rx-2 manual then the rx7 manual should be close to the same.

dvm = digital volt meter

 

The manual will tell you how to test the Alternator and the regulator.

 

engine is running but the alternator is not charging. im lost with your testing procedure