Monitor Volt Watch
My new alternator is acting strange?
Its a custom built 300 amp alternator from excessive amperage and i put it in yesterday and iv'e been monitoring it with a volt meter that i was (watching my stock alternator with) so right away the volt fluxuates from 14.8 to 14.3 sparatically weather there is alot of load or not on it ,plus when im ideling the volts go down to 12.9 then shoot back up to15.0 volts when i bearly accelerate. could it be the exciter wire is faulty or am i just not used to a big alternator like this? the other thing is does the alternator drop
ike that if the battery is fully charged?because i only have one mid sized battery @ moment -exicide-
Your question seemed perfectly normal until you mentioned the voltage fluctuation between 12.9 -15.0 volts. When a new battery is fully charged it should test 12.85 volts with no alternator charge.
Normally after starting a car or truck a volt meter should read 14.3 - 14.6 volts for just a few minutes and settle back down to between 13.5 - 14.1 volts. Too much voltage will boil the acid & distilled water out of the battery. You'll have battery cell plate distortion when the voltage stays abnormally high.
12.9 volts is barely above the normal fully charged battery voltage.
I would call the manufacturer of the alternator and talk to someone in the technical department & tell them what's going on.
