I'm wondering if I have an issue w/ my AP1 alternator. How can I test to see if it is putting out the proper current? Or I guess I should ask where do I put the leads? I have a digital multimeter. What current should it put out and what is the threshold that tells me the output is too low?

 

Connect leads to positive and neg on battery and look for 13.5 -14 volts with engine running.

 

i would also do that test with the car running and the a/c, rear defrost and high beams on. you need to make sure the car is charging while loaded!

as long as it is above 13v at idle whole loaded your fine.

 

Interesting though it seems like I should be testing somewhere around the connector at the alternator to get the true output of it. At least I would think.

 

The "true" output of the alternator as you put it is best read at the source it is intended to supply.That would be the battery. Why do you suspect in the first place that you may have an issue with the alternator? You didn't elaborate in your opening comments. Now if you suspect that the alternator is putting out yet the battery loses charge,then you could have some loose or corroded wiring issues between the alternator terminals and battery.Either way the initial test I would perform is checking the leads at the battery with vehicle running.

 

you should test a both, possibly voltage drop.

 

look go autozone and they can test the battery and the alternator for you while its in the car, for free. how cool is that?

 

Okay, I performed the test and here are the results:

Battery before start up (all power off): 12.67V (dips to ~9.5V when starter is engaged).

With car on:

No electrical load:
At idle: 13.39V
At 3k RPM: 14.41V

Lights only on:
At idle: 14.26 initially then up to 14.32
At 3k RPM: 14.37

A/C only on:
At idle: ~13.5 initially then up to 14.19
At 3k RPM: 14.20

Both Lights and A/C on:
At idle: 14.02
At 3k RPM: 14.12

Turned power off and battery voltage started dropping into the 13's.

 

Alternator seems fine with those readings.

 

I agree.

So WarrenW ,what were your concerns about the alternator in the first place? Did you have an issue or just wanting to test it? Just curious.