You checked fuses and they're all good. So might be time to pull the radio, and check its fuse. Generally they have their own at the back, but while your doing that. Check all the wiring to make sure it isn't burned, melted, rubbed through/chaffed. Cracked or in any way defective. Check all your power wires and earth points.
If your vehicle has them, check the fuses and relays under the bonnet (hood) also. Most vehicles have two sets of fuses.
the little switch in the tailgate. it's the controller for the lock and the feed for the alarm, https://www.ebay.ie/itm/Lock-tail-gate-Jeep-GRAND-CHEROKEE-3-WH-WK-62623-88577/352047650913?hash=item51f7acd861:g:bGYAAOSwsYpaTNYL
Sounds as though you do have a very low ohm reading. With the pos and neg wires connected to the battery, are you blowing fuses or just discharging th battery? A way to isolate shorts that drain the battery is to pull the fuses and see which circuit eliminates the low ohm reading. This is assuming that the ignition key is in the off position. An example would be any light that would operate with the key off. Like the trunk, hood, glove compartment, cig lighter, ECT. Pulling fuses is the only way to isolate. Light bulbs have very low resistance but are controlled by a switch and should remain off unless called go to be turned off. Good luck with your troubleshooting.
If a warning light is on, there's a trouble code stored in the computer. There are well over 800-1,000 possible trouble codes in the average late model vehicle, so asking us to guess what's causing your problem without knowing the code is a complete waste of time. Get the code read. Post it here. THEN we can help
Does the vehicle have spark ? If it does it is not the crank sensor . The ignition switch supplys power for the fuel pump relay directly ,ASD has nothing to do with it . The PCM - engine computer energizes the fuel pump relay by supplying a ground - if it see's a crankshaft postion sensor signal an if no anti-theft system problems . Do you know what a wiring diagram is ? Here free one's http://www.bbbind.com/free_tsb.html Enter vehicle info . year , make , model an engine size . Under system click on engine , then under subsystem click on fuel controls . Click the search button ,then the blue link. Third diagram down.
You have 2 option
option 1 see if the person will fix the vehicle at no additional charges.
option 2 get a special leak detection kit. The kit contains a dye you put in power steering resivor a ivy flashlight and a pair of glasses. Put dye in Reservoir when fluid runs out use flashlight while wearing glasses and look for a glow this will show where leak is. Make necessary repair. Probably a loose fitting or another seal
i think the best way to save your time and money is to take help from the service and repair manual which will guide you to locate and fix the problem with diagram and pictures so that you can repair by your own and the best link to get the manual is http://toolsnyou.com/ i had tried it before so you can also good luck
That's a good start , reading up on the BCM ,but also looking at wiring diagrams an learning how to test electrical circuit's using a DVOM - digital volt ohm meter are need to diagnose these type problem's . Looking at a wiring diagram to see if the BCM even has anything to do with that system or circuit's . Most people on here just jump in an start replacing thing's they have no clue how they work or why. And if you have no clue about automotive electrical testing you really should learn how before even jumping into something like this . An just replace a BCM without it being programmed correctly could make thing's worst .
Plus you need to be aware of other control modules on the vehicle , like on your vehicle ! It has control modules inside the doors , DDM - driver door module , PDM - passenger door module's etc.... The door modules control the power windows an lock's .Plus you need to be aware of that all this modules share info. an send commands to other modules via a serial data network . Your vehicle has the chrysler CCD data bus .
A broken wire inside the flex boot from the body A pillar to the dirver door could cause power lock's an window problems , but would not affect the other problems you are having .
Electric Testing Techniques You Need to Know
Free wiring diagram's here http://www.bbbind.com/free_tsb.html
Enter vehicle info. year , make , model an engine size. Under system click on body & accessories ,then under subsystem click on power window's or lock's an you will see the door modules .Plus the BCM has nothing to do with the A/C not working , A/C compressor does not engage or is it the blower motor isn't working ? no air blowing out the vent's ? Your best bet ,take your vehicle to a qualified repair shop .Takes year's to learn how to diagnose these type problems . CCD Chrysler Collision Detection Data Bus
A loose positive battery cable connection will kill a battery in short order. Tighten all the connections including the starter (usually hard to get at - and most likely the culprit).
It is a good idea to check the cables periodically for corrosion, this can also kill your battery. Once you have made sure the connections are free of corrosion and have a tight fit you can recharge your battery or replace it with a new one if the battery is damaged from being undercharged.
Another thing that will kill your battery is the charging system voltage regulator - if it dies your battery will run out of power just running the engine. Modern cars have this part in the alternator and you may or may not be able to replace the regulator. Take your alternator to a parts store or a shop and have it tested. If it is bad and you put a new battery in the car, the new battery will die.
Try the earth and main active leads to the starter motor. Or If you are shorting the solenoid and it starts, there will be a problem with either the active wire from the ignition switch or a poor earth. Check what voltage you are getting to the solenoid from the ignition switch when someone turns the switch on.