Delco 10SI confusion

[tomfg]

My truck had a Delco 10SI on it when I purchase it. Upon installing a voltmeter in the dash, I noticed it was charging between 14.8 to 15 volts all the time, which I understand is on the high side. Tried various things mentioned on the forums, ie., installing a "generator light" in the #1 "exciter" wire from the ignition switch, moved the #2 sensing wire to the horn relay, etc. (it was jumpered to the back of the alt.'s "bat." terminal.

Anyway, those fixes didn't lower the voltage at all.
Rebuilt the alternator with a kit, and no change.

Purchase a rebuilt alternator, and I figured it's nice to have a spare
anyway. It's still charging just as much, and when I stared up the truck
onces yesterday, the voltage meter pegged out to 16 volts for a couple of seconds, then dropped down to 15 volts.

I went on a 90 mile "shake down" cruise yesterday to see how
everything did, and I ran the headlights and heater blower
the whole time, as I'm afraid of boiling the battery.
Of course, it appears I have a "maintenance free" battery,
and I can't pry off the top plate to check the acid levels :-)

Am I possibly overlooking something in my wiring that
would make the voltage operate so high, or am I
worrying about nothing?

[awbrown]

lots of smart guys in the electrical section..........

[chevy_mike]

Are you sure the gauge is not misreading? Got a digital volt meter you can verify the reading? That would be the first step. Verify the simple things first.

Good luck.

[tomfg]

Verified readings with VOM at battery.
The dash gauge may be a little high,
but not much.

[chevy_mike]

Ideal charging voltage is 13.8-14.4, so what is the VOM reading? Dash gauges are notorious for being inaccurate. When you say it might be a little high, remember you are dealing with a fraction of a volt. If you are reading on your VOM meter 14.4 but your gauge is saying 14.8, the VOM would be right and you are okay.

[tomfg]

Checked it out this afternoon.
The dash gauge is reading about 2/10th's
higher than the VOM reading at the
battery.
When I first started the engine, I was
getting 15v at the gauge, and 14.84
on the VOM.
Went to town and back, and was then
reading about 14.8 on the dash gauge,
and 14.63 on the VOM.
The dash gauge did not "peg out" today
any time that the engine was started,
but mysteriously did once yesterday
for a few seconds.

[chevy_mike]

How old is the battery? If you have a bad cell, it could be keeping it down enough that the alt is trying to continue charging it. What is your VOM voltage after it has sat for 6 hours or so. Turn on your headlights for about 5 minutes to remove the surface charge and see what the voltage is. If it's not holding around 12.5 or more volts, it is very likely you could have a bad battery.

[tomfg]

The battery is less than 2 years old. It's always cranked
and started the engine fine, but your idea might
be fun to try. Thanks.

[JimQ]

I notice you're from MN. I'm not sure how far North but generally speaking the colder the temperature, the higher the charging voltage. 14.8V doesn't sound out of the ordinary in cold weather. I'd run with it and enjoy the bright headlights!

Q