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.

thanks for wirting back..Ok i did have the alternator tested they said it was going bad ..and thats why the 3 lights are on the dash
But would that make it run really bad ? a bad alternator? because some times in the am it's just a slug putt putt backfire and some times it's half runing good and half bad ..Not sure if this makes sence..
also my water from my radeator was draing fast could not figure where it was going ..i think i got that fixed ...No water in oil ..oil looks fine ..but also my water was turning red for along time..ok let me know what you think ...thanks guys
Mark

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.

Ok did the drive test ...took the two wires off and no back fires put them back on i got back fires..And when i put it back on..U could hear
like a winedown type sound thats when i was puting it on..It was still
kinda of rough but no back fires and the 3 lights went out..What's my next move ? Thank you again for all your help
Mark

oh one more thing there is also a strange oder when it back fires ..like solfer or some type of hot springs smell ..not sure what it could maybe somthing to do with the Ac ..thanks again

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.