Anyone know off-hand what the voltage should be at the battery with the truck running (I've got a 98 with the 5.2 for reference) I believe the alt is the 136 AMP. Mine read 13.3v at idle... isn't it supposed to be 14.4v? I'm curious if I should replace the alt now befrore it gives me problems, although it's $150 from Advance.

 

13.3 is ok, as long as it's not at 12.5ish or below... swapping it is easy so i'd wait until it quits on you.