Coming home Sunday from our 1300 mile trip on I-35 near Hillsboro TX I noticed the bus voltage gauge start climbing, 13.5, 14.2 14.8, 15.2, then to 16 volts. I pulled over and measured the alternator output with my digital meter and it was 16 volts. I pulled the belt off and used the genny to charge the bus batteries through the Trace for the last 4 hours of the trip.I went out today and rehooked everything and the voltage is back to normal 13.9-14.2. The only thing I can say is that when it went cuckoo it was raining really hard on the trip and things were really wet back in the engine room. You think that is what caused it? What else should I check? I'd hate to get out on the road and have it do it again. I'm glad I keep a constant scan on my gauges. That would have boiled out my starter batteries really quick. This is a Neihoff 350 amp alternator with a strap on OEM voltage regulator. David
Tom,Where did you get your new regulator from?What does the new one go for?I still have the egg carton one and want to replace it with something a little beter, but keep the old for an emergency. Cliff
Same as Brian. Got mine from C&J. I did have to run a new wire direct from the battery to the regulator, though, as it was not regulating well when connected into the old wiring. Too much resistance someplace was causing the regulator to fluctuate. Running the wire direct from the battery made it rock stable!
A word of caution. I did the same thing but had to run the hot wire from a DC source that was hot when the ignition switch was turned on. Otherwise, there was a continuous drain on the battery which would discharge them in a couple of days. Richard
I called a Neihoff dealer and described the symptoms. He thinks it got wet, somehow. Since it is normal now he recommended a watchful eye. A new regulator is $330. A new alternator is $3500. These things are very expensive. I don't think I could by an off the shelf regulator given the special OEM cannon plug on this one. If I did I would have to get help from you guys about the wiring. It only has 4 wires from the regulator. It seems if the correct connections were made an OEM regulator woulldn't be required.David
Being very alternator challenged, how would I determine these parameters? My tools are limited to a digital tester and not much else.David