charge voltage issues..

slc6oh · Jul 1, 2016

little back story: back in dec I started my truck up one cold day after work, battery light was on for a while while it was idling. pulled into the shop, got the meter out, and checked. wasn't charging. after a while it would go to 13.1 ish

assuming the alternator was weak, threw an alternator on it... no change in voltage readings

come to learn that the alternator don't start charging till after the gp's are off.
battery light has yet to come on , but yesterday out of curiosity I pulled voltage up, at idle ill only be 12.8, running down the road its 13.2...

batteries never dead, all seems fine, but shouldn't I be in the 14.4v range?

DEEZUZ · Jul 1, 2016

In a perfect world yes... but on average all I see all day long is 13-13.8 range

What brand alternator?

mikeeg02 · Jul 1, 2016

Alternators also compensate charge voltage for temperature. Winter months they will be in the 14-14.8 range. Mid summer usually 13.5-13.8 range. (at least in my experiences, YMMV)

slc6oh · Jul 4, 2016

CTC DEEZUL said:
In a perfect world yes... but on average all I see all day long is 13-13.8 range

What brand alternator?

Its a ford reman, because of all the horror stories you hear about auto zone reman ones.. I needa double check at the battery too, maybe just the edge reads different/low.

Zmann · Jul 4, 2016

The single alternator 6.0 is not PCM controlled it just strains to keep up with the GP cycle.

the Edge reads a little low IMO and others have noticed the same

I agree the parts stores Alternators are hit or miss and after taking a new Autozone Duralast gold alternator to install a Marine casing I could see old parts a plenty

Zmann · Jul 4, 2016

My DC Power 190 has read ( EDGE CTS ) 12.8 GP on to 14.1 all it's life
typically around 13.4

04cr450 · Jul 4, 2016

Same numbers with my dc 190 as well. Been like this for 2 years. I agree the edge reads a tad low than actual numbers. The ficm and bat voltages read about a .5- 1v lower.