Jimmy C-6

This is what I do, my friend joked "I didn't know that Vettes are plug in Hybrids".

cclive

One more thing to remember is that alternators are rated at a high speed, not at idle. While the C6 alternator puts out twice what the old GM 10si unit did, both those ratings are at some high rpm...when slowed down to idle, the newer unit may even put out less. Unless you spend lots of time at idle, it shouldn't pose a problem. If you do idle much of the time, then it may be good to have the idle set higher.

corvet786c

Anyone find the fix for this yet?

JPSlick

I don't believe there was a fix because it's a normal characteristic of the vehicle.

When it's hot out and the AC is on, the voltage normally will fluctuate at idle.

However, I'm not sure how your particular issue varies from that.

corvet786c

During start up the volts are reading at 14.2- 13.8, then once it warms up coolant 205 degrees the volts can go all the way down to 12volts, don't know what else it could be. New battery, alternator tested out good. Ground wires tight and clean. New starter tighned wires. Lost?? I know the fans draw alot but the volts would usually go up.

Jimmy C-6

I installed a Billet Tech high output alternator and that solved the problem. Now 14 volts all the time.

Cherokee Nation

GM had 2 engineers working on the DBS problem.Looks like they did not find the problem because the C7's have the same problem I hear, maybe that is why you get a Battery tender with the C7.Corvettes are not the only car with this problem. The high end Super Cars also come with a Tender. My 08 at startup shows 14.7 at idle 775 rpms and when driving with lights and ac on it drops into the 13.5 range with the original alternator. I'm ok with that.
PS.I did have a problem with my battery going dead at times a few years ago, the problem was the crappie battery cable end clamps. After I cut them off and changed to clamps that I could keep tight no more problems....Good Luck

Midlife08

New development in my 08 base model c6....voltage at speed,(highway), is normal 14.2v.. but when Im in traffic, it goes as low as 11.4, and up to 14.1, and all voltages inbetween, had alternator tested, said voltage reg bad, bought reman one, same thing, had it tested, had regulator, did this through 4 alternators, from 3 stores! All with same result? Bought one from a friend, off a 2012 grand sport.. same thing,(haven't tested yet), but fluctuating voltage! Car has stage 3 cam, headers, and tune..had my tuner check the tune can't find anything, had my mechanic check all grounds, and starter..all good? First start in the morning, it's at 14.4...but goes uo, and down from there? Changed my ground Terminal in battery, had battery tested, tested good! I'm at a loss, and it's driving me nuts! Even replaced the alternator pigtail...no improvement?...any suggestions would be great help!

Bruze

I only have shade-tree knowledge of electrics and will gladly defer to the real geniuses here, and there is more than one. But do a search for Dano523 posts. He outlines how to check to make sure the alt and regulator are up to snuff.

If they all check out good, then it seems like a bad/dirty/loose connection somewhere. Also, never assume the dash gauge is necessarily correct. I think Dano's posts address this.

Please post back when you get it resolved.

EVRose

Stop looking at the voltage gauge. If the car starts easily and you don't get any warning messages or codes then don't worry about it.

Midlife08

getting Service charging system message