Hi, new member here so apologies if this is the wrong spot. Anywho, I have a 1999 Grand Cherokee WJ with a 4.0. About a month ago I went out to start the Jeep after it sat for around 3 days. It was misfiring, so I pop my head under the hood and hear the battery bubbling. Stock alt is charging at 20+ volts. So I immediately turn the car off and unhook the alt. Start it up with the stock alt unhooked, still misfiring. I unplugged the front o2 sensor next as a friend recommended me to try it, and with the battery not connected to any alts, it doesn't misfire but idles at 1100 or so RPM. Here's the kicker. I have triple alternators, 2 of which are separate from the stock alt/system. When plugged in to one of my accessory alts charging at 14.4, it misfires again. The stock volt gauge inside the car doesn't work, so I kind of think computer. I am literally so stumped with this, and it's pissing me off to no end as I literally have 20x more than what the Jeep is worth in the build.

 

Anyone? I really could use some love here! Lol

 

My best guess would be a lightly fried computer. but with three alternators you are two and a half over my diagnostic skills. LOL.

 

Lmao. That's great. If it helps at all the other two alts are seperate from the stock system. They're charging a battery bank in the rear of the car. So it's still just the stock alt on the stock system. Lol.