Chevrolet Repair Questions? Ask a Mechanic for Answers ASAP
Hello & Welcome to JA,
Correct voltage when the engine is running & alternator charging is 13.9 to 14.2 volts at varied amps/
The vehicle computer controls the alternator charging system & there is not suppose to be voltage on the 2 wires you speak of.These are the control circuits from the computer.I am sending a schematic & you need to check the wiring & make sure the grounds are good.You may have a faulty computer.