Charging system help

[Defrocked]

So I just recently replaced batteries and my voltage on highway with lights,radio,heater on is just shy of 12v.During the day when lights are off my meter reads a steady 13-13.5v.Believe I have a 70 amp alt and was wondering if this is normal voltage.I did check out the 3G upgrade in the tech section but I'm wondering if I can just have my alt built to 100amp or just go 3G?Also would my voltage regulator having anything to do hear,how can I test this?Had my alt tested at Azone by the way, checked out ok.Basically if I'm gonna put a new alt on I don't wanna deal with re-wiring if possible so I can install myself.Any suggestions to protect my $300 batteries

 

[finitetime]

75amp Alt should run every thing in you truck and still charge the batteries in the high 13v range. There's nothing to up grade the replacement that Autozone sells is a 130 amp alt. They don't offer less so I would think you could have it rebuilt to what ever you wanted. That's controlled by the voltage regulator that built into the back of it.

 

[fordf350man]

sounds like the alternator might be getting week, one thing to always remember is that batteries are only there to start the engine and the alternator is there to run everything once the engine is running, it is NOT meant to charge the batteries however it can put a small charge on them if there is power not being used by other components, one thing you can do for a home test is to start the engine and then disconnect your batteries ( reason for doing this is because if the alternator is weak then it will be drawing power form the batteries to provide the power to the components that the alternator cant ) now turn all the accessories on you can, radio, high beams, interior lights, air conditioning, blower motor on high speed, ect. if your engine and lights start to dim down then your alternator is getting weak and needs to be replaced, or you don't have enough amperage output in the alternator for the vehicle

 

[Defrocked]

Gonna replace the outage regulator then have my alt re-tested at a repair shop...I guess just go from there,really thinking of just upgrading one ay or another since I tow small trailers on the regular.

 

[Defrocked]

Sorry, voltage regulator

 

[laserjock]

I think there are 90 and 100 amp direct replacements. To go higher than that without getting something special, I think you need the 3G alternator. There are guys running them with V belts so don't necessarily let that scare you off.