There will be some draw for keep alive like radio, clock and such but that should be on the order of milli-volts. Have you tried doing a static/dynamic voltage check with a multi-meter AT the battery terminals. Everything off should give you @12.6VDC for a fully charged battery. Running, with the alternator actually output charging the battery you should see something above that static number but certainly NOT ABOVE @ 14.6 VDC. I understand the PCM controls the alternator output but the charging system acts like a trickle charger to replace whatever was pulled off the battery for other things. The overnite unseen killer of batteries can be a shorted diode in the alternator as the diode no longer acts as a check valve to control output but becomes a conductor when shorted. This is usually a result of a "jump start". With no control device between the battery and the diode, current flows and acts much like a courtesy lite left on, the slow draw can take the battery down below 10 volts and it may never recover properly. If you have had the alternator replaced, it had to be replaced with EXACTLY the correct alternator for the VIN. The PCM is looking for the right numbers and will throw "charge faults". Each year there were changes made that the PCM has been programmed to see.
Have you done any SEARCHES on other VETTE Forums looking for similar problems ? Here's an example-
Hey guys, just a question, I went to start my 02 Z up today and it wouldn't start, the speedo/tac/lights all went throught the testing/startup process and then I heard a humming noise but the engine didn't start. Any ideas what could be wrong?
You either have a bad Theft Deterrent Relay (TDR),, bad solenoid,,, or a defective starter. I would also check to see if the main power wires and ground wires off the battery to the starter/engine are in good condition, clean and tight.
Mine does the same thing. If I continue to attempt to start the car, it will start. Havnt had time to sit down and mess with it. Guess, I get stranded one day and have to fix it.
I teach AIRCRAFT ELECTRICAL SYSTEMS and the VETTE is a challenge in the spark department. I'm just a new owner, but I'll cut my arm off before I'll take it to the "Stealer" to get it worked on. I got the 3 vol service manual set and I'm looking for anything I think may help you. I just checked my car - 12.78 VDC static, 14.28 VDC dynamic