Marion Wright

Yes sir I have a 2002 Corvette I keep having a charge system fault on my d i c also my radar detector detects low voltage and an idle I've checked my connector at the battery and the alternator both replace the alternator it still does it also I have an issue with a p 1968 hard coad and c code syste thank you for answering my question. Thank you Marion

Vetteman Jack

GCG

It would help if you could provide a little more info in chronological order about how things happened.

For instance, were you having low voltage problems and drained battery issues, and to solve that you replaced the alternator and now have a charge system fault condition?

If yes, it's probably the new alternator. This is a very well known issue and it's been extensively documented. Even though it might be listed as an equivalent replacement, the voltage regulator inside the alternator is not always compatible. Did you keep your original alternator, or was it turned in as core? If you still have it, it is strongly suggested that you don't let it go, so you can keep your options open.

To troubleshoot a low voltage condition you would need a multimeter to check the voltage directly at the alternator and then across the battery posts. Both readings should be between 13.5v and 14.5v AND the difference between them shouldn't be more than 0.2v (typically 0.1v or less). If the difference is more than 0.2v the connection point at the starter solenoid needs to be checked, as well as the cables in the alternator-solenoid-battery path (you mentioned you already checked connections at the alternator and the battery).

Hope this helps.

Bill Curlee

The voltage to your accessories and, Instrument Panel Volt Meter do NOT come directly off the battery or alternator. NOPE!

All that stuff goes THROUGH the "IGNITION SWITCH". If you have good battery voltage and good alternator output,, The output of the ignition switch is most likely the issue. The contacts inside the ignition switch get burnt and the output of the switch in the RUN position to the modules is compromised. Either clean the contacts or get a new switch.

Like others have stated, you most likely got the incorrect alternator that is incompatible with a C5. Clear the DTCs and see what comes back and post those DTCs

Marion Wright

it all started when my radar detector detecting low voltage at an idle when the air conditioner and radio playing all high that's when I replace the alternator and I do still have my original alternator which I will try reinstalling for The dic. My car has has 58000 mile I replace the battery a year ago I didn't notice any issues until the radar detector started announcing low voltage at an idle with AC on high and radio on loud anyway I will keep checking thanks for everyone's reply and your knowledge. have a blessed day and thanks again! Any suggestions will be welcome. Thanks guys have a great day be careful try to keep it between the mayonnaise and the mustard LOL thanks Marion!

Marion Wright

​​​​ Thanks the chronological order was the battery was replaced after purchase and Men alternator after low voltage on radar detector that's when the IC started saying charge system fault kept original alternator will try reinstalling it any information will be a help thank you and have a great day Marion.

sargentat44711

Thanks Bill I'll give that a try. By the way just a FYI it actually shows on the dash gauge that the drop the voltage is dropping as well would that still be the issue sir if you have time and thank you for your response bless you and yours Marion .

GCG

As explained in my previous post, the charge system fault is the result of an incompatible alternator. Reinstall the old alternator to get rid of that problem, so you can concentrate on troubleshooting the low voltage situation.

Most probably, the low voltage condition reported by your radar detector is being caused by the ignition switch, as mentioned above, but if you want to have a better degree of certainty you can perform the simple test I gave you before. It is just a couple of readings using a multimeter:

If both readings are within the range mentioned above, then the "supply" portion of your electrical system is fine and the problem is downstream from the battery: most probably the ignition switch.

Bill Curlee

If you properly check the alternator with a VOLT METER and find out that it is really out putting a lower than normal voltage, there is an EASY SOLUTION to fix it. There is plastic cover on the back of the alternator . It covers the brushes and slip rings. They get dirty and need to be cleaned with some steel wool or 600 wet and dry paper. Its a very easy fix and can be done with normal everyday tools. Save ya a bunch of money and your OEM Alternator