Tyteflows

DIC voltage reading says 11.6v, but when I read the voltage with a multimeter at the battery or right off the alternator terminal it says 14.4v

Any idea's about what could be causing this drop?

Gordy M

Sounds like the battery has seen its last days, check the battery voltage with the multi meter when the engine is off and sitting for 30 minutes. If it is below 12.5V that means it is getting time to replace.

redzg

I believe Bill Curlee has reported the ignition switch can also be a culprit in voltage disparity.

Vetteman Jack

Moved to C5 Tech.

C5 Diag

DIC voltage is normally about 0.4 volts lower than the actual battery voltage…DIC voltage is read off the ignition 1 voltage which comes from IPC fuse 19…what voltage do you see at fuse 19 with your DVOM ??…what you can do is check the voltage drop between battery positive and fuse 19…one lead of DVOM on battery positive terminal and other lead on fuse 19…what do you read ??

Tyteflows

thank you for the quick response
i will check tomorrow when i get near the car.

lucky131969

Gordy M

Years ago the C5 section reported many problems about about starting, gauges etc. and it was common for someone to measure battery voltage with the car running. GM engineers did some investigating and found that the battery voltage. with the engine off, went below 12.5V weird things would happen, everything from steering wheel lock to not starting. There is a "sticky" about this above. When measuring voltage with the engine running you are looking at the voltage from the alternator (over simplification), not the battery. Hence the testing with the engine off or thate cables disconnected.

lucky131969

Ok, but how does that balance with the OP's issue? The engine is running, and he has a disparity between measured voltage at the battery and the DIC display.