You definitely have something draining your battery or your battery is defective or the battery is not charging.
I suspect that you have a charging problem as you were able to start the vehicle and drive it home ie. you were running on battery power only.....your "red charge lamp" on the cluster may not be working.
Bad grounds do not cause a battery to lose power overnight.
Only the 2006 LHD CRD has problems with the harness behind the Fuel Filter Mounting Bracket.
You need to buy a digital multimeter if you do not have one already.
Charge the battery up to full strength with a charger until it shows about 12.5 volts....check if the Jeep starts and runs without the red charge light on and the battery reading should be around 13.5 volts with engine running.
If this is OK then something could be draining the battery overnight.
If there is a diode in the alternator that has gone short-circuit then power will flow back from the battery, through the bad diode to ground.
Install the battery but leave the red battery cable disconnected.
Set the multi meter to DC Amps...you will have to move the Red meter lead to the socket marked "DC AMPS".
Place the two leads of the meter in series with the Red Battery terminal ie. the current flows from the Red battery terminal through the meter to the Red battery cable...does not matter which way you connect the meter leads as a digital meter will show a minus sign if it is the wrong way around but will not cause any problems.
Do not start the vehicle...the high current will blow the fuse in the meter or blow up the meter.
With ignition OFF, Radio Off, doors closed, interior lights OFF, main lights OFF etc. you should be reading a current draw of around 30 mA ie. 30 thousands of an Amp while the Jeep is standing there as you would have it when parked overnight.
If it is drawing much more...say around a few amps then that is excess current draw...only the ECM, BCM, TCM, radio clock, alarm etc. should be drawing a little bit of current.
First dis-connect the large cable that connects to the alternator...that will isolate the alternator diodes....if the current shown being drawn by your meter suddenly drops down then there is a fault with the alternator....you sure you have the correct type of alternator?
You now have to pull out...and replace... fuses one by one from the panel inside the cabin and then from the box under the hood...when the current draw suddenly drops down to about 30 mA then that circuit is causing the problem.
You will then have to refer to a circuit diagram to trace what that fuse is supplying and trace the wiring to find why there is a high current draw.
I hope when you tried jumping starting with another battery you did not even briefly have the jump cables the wrong way around!
