Figure this one out ! Help

Lets have the alternator load tested 1st if okay -attempt to pull code/s from the computer and if there's any report back with it-we start here

Measure the battery voltage with an inexpensive digital voltmeter while the engine is running. It must be between 13.75 and 14.75 volts. If it is low, suspect the generator or voltage regulator.

AC generators can fail in a number of ways. Did they say what was "going bad"? If a diode fails you will only be able to get one third of the rated output current, but the voltage "ripple" will be very high. That terribly unsteady voltage can interfere with sensor signals and computers and cause those computers to do weird things. To prove if that is the cause of the running problem, disconnect the small wires from the back of the generator, then drive the vehicle a short distance. If it runs fine until you reconnect the generator, it could indeed be the cause of the running problem.

If the brushes are worn, they could be making intermittent contact. That would cause the generator to stop working completely once in a while. The lower system voltage could contribute to running problems but it's not as likely to as the failed diode.

The next test is an in-depth load test on the generator with equipment that can measure ripple. Most shops have something that will fit the bill. If you find a maximum output of only around 30 amps, and very high ripple, replace the generator.