Alternator Status Warning

[gmathias]

I have been parked for two months with the engine battery shutoff turned on. Today I started by motor home to exercise it and when I went to fast idle the "alternator status" light and buzzer came on. If I lowered the idle the light and buzzer went out.
Could this issue have come from turning on the battery shut off and the voltage being too low? The engine did start readily.
I metered across the battery poles and read 16.5 volts across each battery.
Any suggestions?
Thanks,

Jerry

[Robi.1014]

Leaving the engine ("chassis") battery master switch in the ON position didn't cause your problem. The engine starting "readily" (as you said) is an indication that the chassis batt's were not drained all that much (i.e., they were adequately healthy).

But...
A charging system should not exceed high 14 / low 15 -volts range, no matter the RPM.

Perhaps run your tests again: at regular idle, what is the DC-volts measurement?...and is the alt light extinguished (and no alarm). Then increase the idle until the light comes on and the alarm sounds....now take the DC measurement. Increase the idle further...and at this time, is the DC-volts even higher? Where I'm headed with this: failure of the alternator's regulator...which will overcharge our chassis batteries is not corrected.

[crazyfox]

Quote:

Originally Posted by Robi.1014 Leaving the engine ("chassis") battery master switch in the ON position didn't cause your problem. The engine starting "readily" (as you said) is an indication that the chassis batt's were not drained all that much (i.e., they were adequately healthy). But... A charging system should not exceed high 14 / low 15 -volts range, no matter the RPM. Perhaps run your tests again: at regular idle, what is the DC-volts measurement?...and is the alt light extinguished (and no alarm). Then increase the idle until the light comes on and the alarm sounds....now take the DC measurement. Increase the idle further...and at this time, is the DC-volts even higher? Where I'm headed with this: failure of the alternator's regulator...which will overcharge our chassis batteries is not corrected.

16.5 volt will cook the batteries,you have regulator problems,what type of alternator is used on you coach?

[gmathias]

Thanks for your help, I bought a new voltage tester and now get readings of 13.5 VDC. That's more like it.
I also read on another posting that my dash light problem may be caused by being plugged into shore power while running the engine.
I plan on trying again soon, when the park I'm in clears out a bit.

[nplenzick]

I just had the same problem and I thought I needed another alternator, instead the tech found a wire to the regulator was partially broken. All seems well now.