LS7 Amperage
Le Mans Master
Joined: Jun 2008
Posts: 5,284
Likes: 235
From: Rockledge FL
Amperage or volts? Have you had the alternator checked? I was getting low volts and a service charging system message until I put in a a mechman unit and now the DIC reads 14-15 volts constantly
Race Director
Joined: Dec 2013
Posts: 12,502
Likes: 3,629
Are you checking voltage at the alternator, or the DIC.
If at the alternator with the car running and less than 14.7 volts, then alternator could just need to be contact point cleaned.
https://www.corvetteforum.com/forums...nator-fix.html
If alternator is putting out 14.7 with fan, Lights, A/C off, then suspect problems in the alternator to starter solenoid that the battery and alternator cable are nutted together being loose.
Also, double check the negative battery cable connection to the rail for it bolt being loose as well. Hence loose nut at the solenoid will rear is ugly head with slow starter cranking when the motor is hot as well.
Once last thing, and the DIC/ voltage gauge on the dash is telling you the voltage of the ECM, and not the voltage to the dash. Hence power comes from the battery and alternator, goes to the engine fuse box, to the BCM under the passenger toe kick area, then to the ECM. So if not a problem at the battery or alternator, still have 14.5volts at the engine fuse box terminal, then problem is down line, and could be as simple as a loose ground wire for the ECM alone since that is the voltage that the dash/DIC is telling you.
So quick run down, start the car, turn the A/c and light off, and start checking voltages.
At the alternator (rubber boot on the back side terminal, and body of the alternator itself), should have 14.7 volts.
Should have 14.5 volts at the battery.
Should have 14.5 volts at the engine fuse box terminal to the body of the alternator as the ground.
Note, not uncommon for the engine fuse box terminal nut to be come loose and cause problems, so check to make sure it still tight.
DIC should be reading 14.3'ish.
To point out, if you have a Tech II, you can use it check all the module voltages in the car. This comes in handy since the BCM voltage should be around 14 volts, and all the modules down line of it should be no lower than .4 volt drop. If you do have a drop in a module down line of the BCM that is greater than a .4 drop, then it time to check that modules connector for corrosion problems, as well it ground point too.
If at the alternator with the car running and less than 14.7 volts, then alternator could just need to be contact point cleaned.
https://www.corvetteforum.com/forums...nator-fix.html
If alternator is putting out 14.7 with fan, Lights, A/C off, then suspect problems in the alternator to starter solenoid that the battery and alternator cable are nutted together being loose.
Also, double check the negative battery cable connection to the rail for it bolt being loose as well. Hence loose nut at the solenoid will rear is ugly head with slow starter cranking when the motor is hot as well.
Once last thing, and the DIC/ voltage gauge on the dash is telling you the voltage of the ECM, and not the voltage to the dash. Hence power comes from the battery and alternator, goes to the engine fuse box, to the BCM under the passenger toe kick area, then to the ECM. So if not a problem at the battery or alternator, still have 14.5volts at the engine fuse box terminal, then problem is down line, and could be as simple as a loose ground wire for the ECM alone since that is the voltage that the dash/DIC is telling you.
So quick run down, start the car, turn the A/c and light off, and start checking voltages.
At the alternator (rubber boot on the back side terminal, and body of the alternator itself), should have 14.7 volts.
Should have 14.5 volts at the battery.
Should have 14.5 volts at the engine fuse box terminal to the body of the alternator as the ground.
Note, not uncommon for the engine fuse box terminal nut to be come loose and cause problems, so check to make sure it still tight.
DIC should be reading 14.3'ish.
To point out, if you have a Tech II, you can use it check all the module voltages in the car. This comes in handy since the BCM voltage should be around 14 volts, and all the modules down line of it should be no lower than .4 volt drop. If you do have a drop in a module down line of the BCM that is greater than a .4 drop, then it time to check that modules connector for corrosion problems, as well it ground point too.
