Hello

I have what seems to be a strange condition and was wondering if anyone else has seen this or could give me some insight as to where to begin looking.
I do have a good understanding for eletrical issues. What is happening is if I jump on the highway and bring the RPMs to 3500 in, say 3rd gear, the charge voltage
drops to the point of the charge/battery light indicator coming on. I realize these would not be normal driving conditions since 3500RPMs in 3rd gear is pushing more then normal.
But none the less, I don't know why the charge voltage would drop with incresed RPMs.

Thank you

 

what it sounds like is your alternator it is able to push every thing at idle and aroud there but when you give it the gas the engine electrical system requires mor voltage between fuel injection and computer and stuff like that. how many miles does the truck have and do you know if the alternator has been changed since you have had it.

 

Hello

I went out and further isolated the issue. The charging voltage drop is strictly related to RPMs only.
Happens at 3500 RPMs any gear, even neutral with all electrics running (i.e. AC, lights etc...) or with nothing turned on.
I am a factory registered Honda motorcycle tech, so I am familiar with charging systems as far as bikes go.
I am thinking alternator myself due the RPM relation. Once in my years of wrenching I came across
a similar condition on a bike which I concluded that the centrifugal force on the alternator windings was
causing it to cut out at a certain RPM. I don't know if there are any other sensors or anything in this
B4000 charging system that could influence the charge rate at given RPMs.

The truck is a 1999, 94K miles. I have owned it only since April, so I don't know any service history
prior to my ownership. I do know it is super clean and apparently well taken care of.

 

yah that is waht it sounds like is some thing inside but it doesnt make sence that it should just cut out. if it was the windings it would slowly work the voltage down i think it wouldnt just cut out. if it were me i would just take it some were and have it tested.