What should the alternator charge read?

[seth_95]

On my gage my alternator reads about 10 all the time. I just bought this truck and the batterys look fairly new. Whenever I roll up the window or move seat back( power) the alternator gage really drops. It has never gotton above 12 - 14? Any suggestions or is this fine?

[K. D.]

It should read just a hair under 14 volts when truck is running. Shouldn't drop when you run accessories, only thing that pulls mine down is the glow plugs. I would advise running a load test on the batteries and alternator.

First though, get a meter and check the voltage, could be a bad gauge.
A thorough check of all wiring and connections is probably a good idea.

K.D.

[DA BIG ONE]

Most everyone misses cleaning the pos+ cable where it meets the other pos+ cable at the pass side battery under the terminal cover this is the first place I'd look, then all grounds even for the dash.