Hey guys,

Quick question, I have looked in the manual and did a couple of searches here on the forum and am not really finding what I am looking for. I believe my alternator is no longer working but before I go buy another one is there an easy way to test it? I have the volt/amp meter that I can use to test. I have an '85 12A.

Any advice would be greatly appreciated.

Thanks
Bill

 

Take the alt off and take it to the auto parts store. They will load test it.

or do this. It from Chris Fix.

http://ttps://www.youtube.com/watch?v=LGB6ZEjGm7Q

 

Idle the car with all electrical accessories at full (bright lights on, blower on high, radio on, maybe even kick on the hazards for max electrical load. Stick a volt meter on the battery + and - and you should see a minimum of 13 volts for an old worn out alternator. Preferred is 13.5-14 volts.

 

One of the things about Alternators is DO NOT EVER SPIN IT when it's not hooked up to the car electrical system. The voltage diodes in the Regulator will be blown and that Alternator will be dead. Aside from that, the best test is to take it to any auto parts store for load testing. They'll be able to tell you exactly what the output amperage is at specified RPM, and that's everything you need to know if it's in good working order.

 

This is great info guys. Thank you. One last question:

How can I tell if my alternator needs an external regulator? I have had the car 2 years and it did not have one and I never had any issues. I believe the motor is from an '85 Rx7. Is there a way I can tell if I need an external regulator from look at the outside of the alternator?

Thanks again!
Bill

 

All RX-7's after 1980 have the regulator built into the alternator.