I'm just going off the general recommendation.The a/c compressor should be belt-driven, but the HVAC fan will usually draw more power than the headlights or radio. Do the test with the fan on and see if it's under 50 mV. Even if it's a bit higher, it's hard to say whether anything is wrong with the alternator if you don't know what load the spec is based on.
Is 50mV the spec for your specific alternator, or a generic recommendation? Is there a specific issue you're trying to diagnose?
Some specs are 100 mV or more. I'd say it's pretty likely your alternator is good.I'm just going off the general recommendation.
...from my memory.
1) Ripple tests are done at 3,000 rpm (general recommendation)
2) I believe turning on every accessory AND THEN checking the charging voltage at the battery is a diode test.
If the voltage is low (it should be the same as an idling engine with the doors closed and accessories off), you have a bad diode in your assembly. I assume the ripple voltage would be higher.
Probably so. it's not jumping around or anything. The numbers were pretty steady at .035 everything off and .050 with everything on.Some specs are 100 mV or more. I'd say it's pretty likely your alternator is good.
Well it's a diesel, so I'm not reving it up to 3000rpm. This was just at idle. 1999 5.9 cummins dodge ram pickupAt what rpm did you test?
What vehicle/engine are you working on?
What would you do on a diesel? 1500?Well it's a diesel, so I'm not reving it up to 3000rpm. This was just at idle. 1999 5.9 cummins dodge ram pickup