Trying to help friend tj electrical issues
 

A friend has a 98 tj 4.0 it has an intermitant electrical issue
Check gauges light comes on
The volt gauge is pegged above 19 and the lights flicker then suddenly the check gauges light goes off and the voltage is back to normal 13 or so
I'm thinking voltage regulator. But if I'm correct it's in the computer ?????
Does anyone have any experience with something similar ???

These days most voltage regulators are in the alternators. Sounds like it is time for a new one.

According to the jeep service manual the voltage regulator is in the PCM Hoping there is something cheaper rather than replacing the PCM to find out it's a loose connection someplace

Check you chasis to engine grounds. Sophisticated electronics (computers) hate seeing different ground potentials, and will do strange things when they do.

The pcm sends a signal to the alternator to tell it to put out more voltage from what I have seen. The pcm monitors and controls the regulator but unless they have really lost their mind the regulator is actually in the alternator. If that isn't the case then I would be really surprised.