Alternator question.

[dottieshusband]

I've been starting my starbord engine with the parallel while I wait on the new 819's. I noticed that my alternator voltage guage for the Starbord engine reads zip while running. Shouldn't the guage read alternator output, around 32v, regardless of battery condition? The batteries still hold enough umph to start a slow cranking genny, but only click the solenoid for the engine. I checked the battery charger output, It's good, I'll check the actual alternator output tomorrow..to late to fire them up tonight. But shouldnt the dash voltage gushed show alternator output even with bad batteries??? Thanks

[davidwigler]

Did you mean "zip" as in 0 volts? If so that is definitely a gauge problem.

[Nonchalant1]

Maybe it is a sulphated battery. A sulphated battery will return a false high voltage reading even though it is almost fully discharged, which shuts off many types of alternators and chargers because they stop charging when higher voltages (like 37.5) are reached.

[dottieshusband]

Thanks, I'll check the output voltage down stream from the regulator, but you are probably correct. I hadn't considered that option!

[davidwigler]

But if the sulphated battery was shutting off the alternator because of high voltage the gauge should still not be reading "zip."