Hey there, SO I dont know if im just being lame or if theres really something going on BUT Ever since I got a new battery and cap and rotor my trucks been running great EXEPT the battery voltage is fluxuating....I dont know if I just never noticed this before and its normal or what but it seems like something is draining the battery, maybe the alt is bad?
When im stopped at a light the voltage will go from a strong 12-13 down to about 8-10 and back up and down, Lights will dim and then brighten again the radio will sound quieter and then back up (barely noticable)....also if I roll up the back windows at the same time the batter goes down half!

Any ideas? thanks guys!

 

Maybe take your alternator for a bench test? I thought the "battery" gauge measured alternator output, but I'm not positive on that.

 

Are your ground wires all tight .

 

deff do the alt test. might want to have the batt tested too to make sure it's able to hold a proper charge too.

 

I just got the batt like 2-3 weeks ago because my other one was half gone.
I have always thought something was not right with the alt...I will get it tested.

I dont know about the wires...will check it out.

 

i suggest the batt tho bre cuz when an alt craps out - the longer it runs on the bald alt eventually the battery craps regardless of age. 2 more bolts to have it tested @ the same time and if its crap u've owned it 3 weeks - WARRANTY !!!