We have a 2000 jeep cherokee. My husband (not me) used the wrong connections of the cable jumping the car when it’s battery died. Now the car computer is locked in and we can not start the car
How do you know the “car computer is locked in”? What is the “car computer”? Do you mean the “engine computer”?
If you are very lucky…Check the ECM fuse in the fuse box. If the ignition switch was OFF when the jumper cables were mis-applied, the computer may not be fried.
If you need another computer, a salvage yard could help. Cheap.