I have a 96 jeep Grand Cherokee that the alternator charges intermittently. I can drive it and let it sit for a while and then try to start it and it will not do anything. My mechanic looked at it and said it has a open circuit. He had his test light on the battery with the key off pull the 50 amp fuse and the light went out. What would cause this? What does that 50 amp fuse control?

 

Welcome to the forum! Hey if you repost your question here you will get a better response:

https://www.cherokeeforum.com/f5/

That's the forum for Grand Cherokees versus this one which is for the Cherokee. You can look in the manual for a fuse diagram to identify the fuse. Or sometimes it's inside the cover if it has one. I did look up your fuse diagram and the only thing I see at 50 amps is the asd "relay" so not an actual fuse. It controls the fuel system prime, providing power to the fuel system until the pcm gets a signal from the crank sensor. I'm sure the GC guys will get you fixed up.