Anyone got any idea's on this?

Just started the other day.
Occasionally it stops, but video tells all.

is there a different voltage sending unit for the gauge as opposed to the PCM?

YouTube - ‪June 12, 2011 09:58‬‏

yes yes, please make fun of my ghetto gauge mount, but it works. :P

 

I would say that it looks like a wire might be loose or something like that, but it's just a guess.

Red

 

I cannot find anything. I took a 1 hour trip to a guys house, and it did it on the way home. just kinda weird.

 

What happens if you put a meter right on the battery while it's running?

Red

 

Mine does the same but only at Idle. I unplugged the alt and tried to clean the connections. It seemed to help but still pulses.

 

William,
Something is not right.
Does the CEL come on too?

I had 2 trucks that the main wire that goes from the alternator under the pass battery tray (or maybe degas bottle?) tot he fender solenoid rubbed through and was causing a pulsing CEL.

But you should not be seeing charging that high.
It almost looks like the PCM is trying to maintain 14.2 when voltage jumps up that high and that's why you're seeing the pulsing?

Have the alt checked at a parts store?

 

I'll check it later today, My truck has always charged high though.
14.6 is normal for it.
So it is a bit high.

I'll be sure to inspect the wiring as well.