I'm working a overnight at work, I just left for lunch whenever I came to a stop my check guages light came on and the voltage dropped, all lights dimmed. This was happening a bunch of times, if I kept my foot in it with the truck in neutral it was fine, towards the end of my 3 mile total trip I had to keep the revs above 1500-2000. As long as my foot was in it the voltage guage read 14 volts. I have underdrive pulleys would this cause it? I know the guage drops at idle from them. New battery also less than 2 months ago.

 

first off, put your truck info up. second, take it to O'riely's and get your charging system checked.

 

Sorry I'm at work using my phone to get on the site I was trying to see if I can get home or not. It's a 98 ram, stock with underdrive pulleys. The alt was tested a month ago.

 

yea but an alternator can burn out in one day, it seems thatwhen you hold the revs, its creating a charge. Start by checking all your connections

 

i would bet on a new alternator, if your old battery you replaced was weak your alternator was working harder to keep it charged. +1 on J415 get your charging system checked

 

Wayfast, you do realize with underdrive pulleys, all accessories turn slower? Meaning, your alt is turning less rpm, hence less voltage. So at idle you may only see 10-12 volts. Are you running just the crank underdrive or the crank and alt pulley?