Overcharging

[phattruk]

i have a 2001 silverado 4wd 1500 hd. bought it about 18 months ago. truck has a plow gear, single batt setup(batt 8 months old). the alt gauge has always read over 14 and close to 16 since i had truck. this evening on way home my som tells me the gauge went all the way to the right and batt light came on while driving. at idle the gauge drops a little and batt light will cycle off and on. i'm thinking this is most likely a regulator issue. if so do i need to replace the whole alt or can i swap the regulator? i just rode the truck 500 miles for a saturday fishing trip with no hiccups. guess i should be happy it occured close to home...

[GMTech686]

Voltage regulator is internal. Serviced as complete unit

[phattruk]

just for the hell of it i went to start my truck and the battery was too weak. not sure why. when the alt was overcharging and i turned truck off, it started 3 hours later with no problem. i noticed the battery ground was a little loose, so tightened that, charged battery for 20 mins, started truck and the alternator gauge now sits at a hair past 14. i cut on every accessory i could and gauge stayed where it was. took truck for a ride and still no overcharging alt. i misplaced by voltmeter so i couldnt see how many volts the batt was kicking out while truck was running. now i dont know if its the alt, battery, or the loose cable that caused the problem. would the loose cable cause the alternator to overcharge. i've had loose cable in past and never saw this.

[Doug_Scott]

You can replace the internal regulator. But, if the alternator has been overcharging for a long period of time it will burn the stator windings. A bad connection can cause an overcharging condition. You may have just gotten off lucky there. I would take the truck in and get the charging system checked over properly though.