Checking alt. Output ?

[jtward]

I'm not too good with automotive electronics's. But I have a basic multi-meter. How do I set the multi-meter to read alternator output. It has AC /Dc setting and positions, but the instructions are pretty vague and I'm not sure how to do this simple procedure. Thank you 2003 Corvette LS1. Thank you !

[LLC5]

Originally Posted by jtward

I'm not too good with automotive electronics's. But I have a basic multi-meter. How do I set the multi-meter to read alternator output. I has AC /Dc setting and positions, but the instructions are pretty vague and I'm not sure how to do this simple procedure. Thank you 2003 Corvette LS1. Thank you !

For alternator output you need an ammeter that will read over 130 amps, and and inductive one would be the safest to use. To check and see if your alternator is operating properly, you can use a voltmeter. Voltage readings are more important than amp readings, as you can't have good voltage with out amps. Get the vehicle warm (hot), and turn on all the accy's (a/c, rear defog, high blower, high beams, etc) then put your voltmeter to dc volts and install it on the battery. Check the voltage at idle, then rev the engine to adout 2000 rpm's and check voltage. It should be above 13.0-13.2v with all accy's on and engine hot. 13.8-14.0v is ideal, but the alternator in these vehicles are computer controlled and will keep the voltage down when hot. Starting the vehicle cold, you will see about 14v on the gauge when running then when the vehicle warms up the voltage will drop to near 13v, this is considered normal. Good luck with your testing.

[vettex2]

You also need to check the diodes