changing the voltage regulator

My first question is why? And the regulator is built into the alternator.

when I pulled codes it indicated the voltage was fluctuating. I had the battery tested and the alternator as well. I was told to replace the voltage regulator. what started all this was my headlights flickering. I had already cleaned the connections on the ground wires.

Can you post the code numbers here, so that I can review them.

53 and 23

Can you give me the 8th digit of the VIN (Vehicle Identification Number) code. It will be one of these: X, W, 3, or R

Or if not the VIN code, the type of engine you have. 4 cylinder, 3.8L 6 cylinder, 2.8L 6cyl fuel injected, or 2.8L 6cyl carburetor.

Code 53 is "system over-voltage (ECM over 17.7volts)". Make sure your battery cable ends are clean and tight. Disconnect the battery cables (negative/black) first, remove the terminal bolts from the cables/plastic (Just push them out), clean the cable ends with a wire brush or sandpaper. Clean the terminals on the battery, and reconnect the cables (positive/red) first. Tighten the terminals. Check if you can move the cable ends (loose). If you can, you will need a new terminal end for the cable. As for the code 23, I will need the engine info.

engine is a 2.8L V6 Fuel injected

Code 23 is for the Intake Air Temperature sensor. It's a 2 wire plug that is located on the intake boot, between the air cleaner and throttle body. Make sure this is plugged in, and that the wires aren't broken. This could also be an old code, if it had been disconnected before, and the ignition was turned on. Meaning, during a repair.

I correct myself. The air temp. sensor might be screwed into the air cleaner, on this model.

Thank you for the input. I will work on it tomorrow and post my results.