Alternator Surges
 

So any ideas when when i hit a bump my alternator surges and my gauge fluctuates? You can feel the truck get jumpy as the alternator turns on and off rapidly. Once again it only does it on bumps like a rough road.

sounds like you have a short i would look for bare or pinched wires

when my truck is cold the alternator fluxuates from 12 to 15 volts but it doesnt affect any of the other systems on the truck, except that the lights get brighter or dimmer. i dont know if this the same as ur truck but i just figured it was the alternator cycling or something. i never really worried about it.

Mine goes all the way left and back numerous times a second. I verified that it wasnt a short. All wires going to the computer are in good condition.

Figured this one out this morning guys. The ground wire that runs from the battery to the radiator support broke. Fixed wire= fixed problem.

i had the same problem on my 91 it would drop down to like 5 volt and then jump back up to normal it only does it in the morning for me,i think it might have something to do with my remote start:rocking:,but now that i think about it i might go home and check that ground wire see if thats the cause:ouch:

my buddy had the same problem. he lost his lights and everything though. sounds like a pretty common problem. probably not a bad thing to go ahead and replace or make sure it is good and tight so it doesnt give you problems at a bad time...like a curve at night :scare2: