Engine won't turn off...help please

Does anyone have any ideas as to why my ignition won't shut off with the S164 coolant fan fuse connected? ...

My large fan went out recently, so I replaced it only to find that the AC compressor would cycle off at idle and back on while driving. I searched online and decided that the Fan Control Module was probably the culprit. I replaced the FCM and still the AC was not operating correctly. I searched online again and decided to check all the fuses associated with the AC system. I found a blown 40A fusible link in the cable box directly above the battery, it was #3, S164 for the coolant fans. I thought again that I had found the culprit, so I replaced the fusible link only to find the AC compressor would not turn on at all. I was about to move on to troubleshoot other possible causes but quickly discovered that engine wouldn't turn off when I turned the key off. It is definitely an electrical issue, the instrument cluster dummy lights and my AC recirculation light stay lit even with the key off. In my attempt to back-trace my steps I discovered that if I disconnected the #3 S164 cable on top of the battery the car turns on and off just as it should. What did I do?!? I feel like something must have shorted out or melted wires together...or something.

bump.

Make sure the FCM/fan grounds are OK. This one is in the engine compartment under the battery.

If the FCM grounds were bad would that have any affect on the car's ignition system? I'm trying to find a relationship between the AC wiring components and the the ignition system wiring...I guess I need a wiring schematic.

An open ground can cause power to backfeed through another circuit that has a path to ground. I'd have to look at several diagrams to figure out the exact path, so it's easier to check the grounds.

Gotcha, I'll definitely check. To clarify though, I should be checking the grounds going into the FCM via the 2 connectors? ...or are there other grounds under the battery I should check?

It's a stud terminal under the battery and battery holder tray.

Ok, so just make sure it's still grounded? Not melting? What should I be looking for at that particular ground?

Corrosion, looseness, or broken wires.

Cool, I really hope I find the cause is there but I get the feeling something screwy has happened b/c everything was fine a couple days ago.

If you have any more ideas please let me know...and thanks so much for your help!