07 Jeep Commander

I am going to assume you have four wheel drive since you did not say.

With a flashlight, slide under the drivers side of the vehicle, behind the front wheel.

Look up and locate the starter motor.

You will be able to see two seperate power wires, wrapped in black convoluted tubing, one larger in diameter than the other.

You are going to be jiggling the smaller diameter wire, close to the body of the starter motor......most likely, you will have to use a ruler or piece of wood as an extension to sneak past the front driveshaft.

Don't push too hard, just kindof jiggle the harness as best you can.

Come up for air and try to crank it......if I am on the right track, it'll start or crank momentarily, then back to click with all the dash lights.

Either case, this means that the wire (the small one) has corroded between it and the slide on, spade terminal on the starter.

In the event it starts, you have fixed nothing.....it'll do it again in a day or two."

(Robby-https://www.jeepcommander.com/threads/jeep-wont-start.17187/)