I had both the battery and alternator checked out. The bat. and alternator was said to be ok, though it had a jacket that was melting inside (fixed) and some wiring fixed, as well as the at idel noise these start to make after a while. The repair place said these altinators are bullit proof, and said these repairs would resolve the issue.

Anyhow, volts still take a while to build up and at times it just stays at 10volts so I still have the same problem, with the car telling me it has Charge system errors! Some times it makes 13v like is supposed to, but only at random.

What should I look into? This is annoying, I want to get this resolved, so can do a tune up, and get rid of the crappy GM leather so I can start enjoying the car again while we have this nice weather for some time to come. Could be stress with work and such, or the general lack of skilled people in my town or a combination of both but my Corvette Experience isn’t what it used to be, and I'm a hardcorve vette fan

I don’t want to deal with GM quality issues anymore, and is why I’m going to wait for the c6 to be out for a while. Tired of fixing seats that rock with $500 parts, and the other common things I won't bore you with. However, I don’t know another car that gives near the same performance value while looking pretty good. If someone does GM better watch out. Ok, done venting… Sorry

 

The PCM monitors the alternator through the red and grey wires If you eliminate them,you will have a problem...Read the description below:
The L-terminal circuit from the generator is a discrete circuit (a discrete circuit has no splices and only one source and destination) into the PCM. The PCM applies ignition voltage to the generator L-terminal circuit. A small amount of current flows from this circuit through the generator windings to ground to create a magnetic field which starts the generator process. When the generator is at operating speed and producing voltage, a solid state switch for the L-terminal circuit in the generator opens and the PCM detects that the initial startup current flow has stopped.

The PCM expects to detect low voltage on the L-terminal circuit prior to the generator rotating at operating speed and conversely expects the circuit to be at ignition voltage potential when the generator is operational. When the PCM detects a fault (circuit shorted to ground, or circuit shorted to voltage), the Driver Information Center will display Charging System Fault.

The generator has an input to the PCM called the F Terminal to indicate the percentage of total capacity that the generator is producing. This signal is detected by the PCM as a duty cycle from the generator and displayed on the scan tool as a percentage. The PCM can monitor the generators output under all conditions to determine if it is functioning normally.

When there is low demand from the electrical system on the generator, a low duty cycle percentage will be displayed. As more accessory load is placed on the generator, the duty cycle output detected by the PCM will approach 100 percent. A normally functioning generating system will never reach 100 percent as indicated on the scan tool.

The L and F terminals are the red and grey

The alternators are not bullet proof.. you should be seeing 13.8 to 14.1. if your seeing 10s and 12's you have problems..

 

With the alternator off the car and tested it came out ok? Someone posted here also that a dealer GM tech has yet to see one of these alternators fail, and the alternator shop said the same? Seems like the problem is somewhere else then the alternator physically. I don’t want to leave this car with the dealer who will no doubly rape me with extra fees like diagnosis, and more then likely brake something else, but doesn’t seem like I have much choice? The alternator shop can’t see the car again until Thursday and I already paid $125.

 

My alternator on my 99 went this summer... bullet proof?? I think not..
Ive seen many post on charging system faults and alternator replacements, most dealers carry a few alternators in stock. if your DIC is seeing 10's and 12's the alternator is not putting out enough to keep up with the demand.. Ive not seen any indication that your car has any extra sound equipment , so if your demand is stock and your seeing 10and 12's, you have either a bad battery or a bad alternator or voltage regulator.

 

check the wires around the starter. make sure there tight and free of rust

 

I do have a small system with a 10" though I have had it for a long time now with no problems. The car also has an underdrive. I should be seeing 13s which was normal with my setup for over a year. Maybe I should just replace the alternator, I don't know why the shop would have tested it as OK if it is not?

 

TexCorvette,

My experience with the DIC message, "Charge System Fault":

When starting my 1999 C5 coupe, I would receive this message intermittently. Several trips to the dealer did not resolve the matter (then it was still under the new car warranty).

The dealer mechanic finally called Chevrolet Technical Assistance and was told to check ground locations on and near the starter, under the battery tray.

He found several nuts loose on ground studs. He removed the nuts and cleaned the ground location studs, then installed the nuts and tightened them. That eliminated the DIC messages. (This was not related to leaking battery acid - that happened later...)

The mechanic stated that Technical Assistance immediately knew what the problem was and it must have been an assembly problem. My car was built after the infamous UAW work stoppage.

The car was/is always garaged and never driven in rain or snow. You may want to check these ground locations. Good luck.

 

I expect you have long-tube headers and the heat has melted the wires that attache to the starte solinoid. It is a bitch to get at, and you probably need to pull the pasenger side header, but I bet you will find charred wires and a loose or bad connection at the solinoid or a possible melted wire leading to it. Good luck!