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73-87 Chevy _ GMC Trucks => Performance => Topic started by: rdhack on September 05, 2007, 12:09:39 pm

Title: Alternator Diagnosis
Post by: rdhack on September 05, 2007, 12:09:39 pm

Would an alternator be going out if when the AC is on the voltmeter gauge goes really low towards the red line and back to normal when the AC is off??

Any quick reply will be greatly appreciated.  1994 C10 V6 with AC

Title: Re: Alternator Diagnosis
Post by: VileZambonie on September 05, 2007, 02:29:10 pm

You need to actually check it with a volt meter. Turn the AC on and all electrical loads. Run the engine at about 2000 RPM and post output voltage. Also list voltage at idle and with all accessories off engine idling.