Big Red Battery

[92Blue]

For some unknown reason, the DIC displayes a charging system light. The battery tests at 12.3 volts and when running, 14.4 volts. I just installed a new Delco alternator and battery. Nothing changed. What would trip this code? Previous symptoms were power surges heard/seen through the blower fans and head lights when activating the right turn signal. Thanks for your help!

[94 Jimmy]

What year?
It sounds like your battery, and charging system are OK, check for improper grounds. On my 98 there is a stud on the inner fender wall near the negative battery lead where all of the ground circuits return. Current flowing to say the headlights must find a low impedance return to the battery or it will cause a voltage drop across any resistive connections. This means less voltage across the headlights and a dimmer bulb. Add other pulsing currents, say to the turn signals and you get a headlamp that brightens and dims in sync with the turn signal.
A prime example of this was the older Audi's that tried to use the body work as a return electrical path. Following one making a right turn with the break lights on was a joy. When the right turn signal came on the left break light went out when the turn signal went off the break light came on. What you saw was a set of lights flashing left, right, left,....
Check the ground wires at this point and look for loose ones. If you've had any body work done, check that the body shop reconnected all of the ground leads and didn't leave any screws out that might be a ground path.
The voltage monitor might be seeing 14.4 volts at the hot side of the battery, but if it has a faulty ground and sees the low side as 2 volts it sees only a 12.2 volt difference and thinks there is a problem. It's an easy fix once you find it.
Good luck
94