Q: On my 3rd alternator, different problems with each one, starting to suspect it may be a compound issue.

asked by

Brian

on June 09, 2017

So I'm on the 3rd alternator for this car that just started having the battery light come on. 2004 Crown Victoria Police

1st (original) Alt - Needed to be revved to start charging, and then only outputted 13.5 volts (never varied), which is low enough to cause battery light to come on and stay on constantly.

2nd (junkyard) Alt - did NOT need to be revved to start charging, but also only outputted 13.6 volts, which again is too low and the barttery light was constantly on.

3rd (aftermarket) Alt - does NOT need to be revved to start charging, when cruising at a constant RPM it outputs too low (battery light comes on), but when the engine is under load (not high RPM, just load) it will jump up and start swinging erratically in the middle of the gauge (don't know exact voltages).

Say my dashboard battery gauge was a scale 0-100, when cruising it is at about 35 (same as first 2 alternators), but then under load it starts swinging from 45-65 range, which fixes battery light temporarily.
My car has an automatic transmission.

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Q: On my 3rd alternator, different problems with each one, starting to suspect it may be a compound issue.

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