Hi all, I recently purchased a 98 Grand Cherokee ZJ. The PO said it had a stalling issue where at random times would shut off, would sometimes start or wouldn't start for days. The battery would also die (hmm). Ok, I thought it could be something non-electrical like a Crankshaft Sensor or new Cap and Rotor. Now, my findings seem to convince me its an electrical issue. I originally posted some information about connectors not being connected in the "Grand Cherokee Ask the Questions thread, but I need further assistance where my own thread would prevent over-posts.

It seems the car used to have a aftermarket security system in the vehicle because it was left under the hood all disconnected so I first went about tracing its wires to remove them and cap off any possible connections. Well, I found them and both were dead, not connected anywhere. I then checked the connections, fuses, relays and wires under the glove box. No splices anywhere. The PO did temper with the old cigarette lighter and replaced it wish a usb port, but didn't wire it in. In that cigarette lighter harness that plugs into the main harness, he spliced in two additional black wires and used the red power wire from the cigarette lighter to connect the three wires into a switch which was no longer connected as well. Here are some pictures to help justify.


This was behind the glove box unplugged it seems factory, I figured this was an option for an additional feature my jeep didn't come with?



This was unplugged when I removed the ac/heat cluster and found where it plugs into. What does this do?


Heres an additional wire PO added, but wasn't plugged in anywhere. I don't think this is a problem, this harness is located below the passenger fuse cluster.



Here you can see where the PO added an additional 2 black wires on the left and changed the red wires connector which he had all three connecting to a dead on/off switch.


Now why I started my own thread. After checking all the relays, fuses, wires and plugs in the passenger foot well, I plugged them back in. While plugging them in, my radio unit starting making a weird clicking nose Then, the Courtesy Relay went crazy, clicking! It won't stop! I found which one it is and tried replacing it with the other three in that fuse box unit, but it still continued clicking. It got even worse, my automatic interior lights shut off and the car dash lights wouldn't come on. The car wouldn't even turn over, click or start. I can lock/unlock the car, and turn on the headlights, but the lights are very dim. The entire car has barely any power. The horn barely honks. I checked my battery cables/terminals and wiggled the wires under the dash, still nothing. I checked my battery with a DMM and it read almost 11V. I definitely believe the car is grounding out somewhere which is why the battery would die when the PO had the car. Sometimes the Courtesy Relay would stop clicking and start again. I disconnected the battery and tried re-connecting, but nothing. I plan on doing a Fuse/Relay Drain Test with my DMM tomorrow to pinpoint where I should start diagnosing. I have car intelligence, but when it comes to electrical I am screwed lol. Any suggestions would help! My apologies for the long thread, but the more details, the better you can all understand. Thanks!

 

Update:

I did a parasitic drain test and the jeep has a .176A drain. I read on here normal is no higher than .50, but should be .30. What is odd, if I leave the DMM connected the reading after a minute goes from .176A to .30A which is the normal drain #. Does this mean the system is shorting out only sometimes? I ran through all the fuses under the hood and the Red 50 fuse when pulled dropped significantly to .002A. On the fuse pannel it says this is MUX/T TOW.





I then checked the fuses/relays in the passenger side foot-well. I'm unsure what this fuse is for if somebody could clarify, but when pulled the reading dropped to .80A? Is this a significant enough drain that should be inspected?



Besides those two fuses that have drains, I discovered that when I open any door with the ignition set on to accessory, the Courtesy Lamp Relay 19972J clicks like crazy. When I close the door it stops and when the ignition is set to on and not accessory, no clicking occurs. I'm stumped!

 

Currently having same exact issue… PO had what looks like an after market security system wired and its had some weird electrical issues since i bought it. Please let me know if you found a fix!! Even if it was just cleaning a battery terminal lol, new to the jeep and self diagnosing world but thanks in advance

 

Ended up being extremely dirty caked up battery terminals that I cleaned very thoroughly and voila! Was experiencing the same exact symptoms though lol