I have the Leece Neville heavy duty alternator that came with the RV. When I first start the engine the voltage gauge will bounce between 12 volts and 14 volts and the dash lights will dim along with it for about 30 seconds to a minute then it stays steady at 14 volts. Is this behavior normal for these alternators (does it need a bit of time to warm up the diodes and/or establish a magnetic field) or am I looking at a new alternator in my future? Thanks.
Quite likely, the INTAKE MANIFOLD HEATER is cycling. It takes a LOT of amps.
Does this occur only on cold startup or on warm startup as well?
Sounds to me like all is normal. As Brett said intake heater cycling on and off.
It only does it when engine is cold. Once warmed up it stays 14v. So the drop in voltage is just the heater kicking in. Good to know. Thanks for responses.
14 is too much for almost any batteries at 77 degrees. At 30 degrees about right. Almost one volt over at 100 degrees,
Not a problem except for long stretches on the road