Originally Posted by Corlauv
I mean that it cranks with a screw driver. I also just used a test light and when I have a friend crank the jeep while I have a test light down by the starter where the power is sent to it when you crank it, the test light does not light when he cranks the jeep.
I think we can figure this out without shotgunning parts at it. This statement seems like a a good clue and gives a place to test further.
My spot I could check next is the Starting relay at the power distribution center. Find the relay and pull it. There are 4 pins under the relay that you want to check.
There are 2 load side pins. This is the switched side of the relay or the relay will connect these two pins when relay is switched on. One pin is from fuse 4 which is a 40amp (pin 30 on relay). The other pin goes to the starter solenoid down on the starter motor (pin 87).
The 2 control side pins are what enables the switch in the relay. One pin comes from the ignition switch and will have batt + in start (pin 86). The other pin goes to ground (pin 85). This should be grounded if the auto trans is in Park or Neutral Or on a manual, I think it goes straight to ground.
Now how to test this....
Take a test light. Connect clamp to ground or batt neg. Touch each of the four pins. One should light all the time. This is the load side that comes from fuse 4. This is pin 30 on the relay.
One pin should light when key is in start. This is pin 86 (it may be 85). This is power to the coil or control side of the relay.
Now connect test light to battery pos. Touch pin 85. This should light the test light all the time if it's a manual or in Park/Neutral on an auto.
With the test light still on battery pos see if you can find pin 87. This is the pin that goes to the starter solenoid. If the starter solenoid works, it should lightly light the test light. It's a path to ground so should light the test light a little. I am not 100% certain in this but it's worth a try. Also a DVOM should show continuity to ground as an alternative.
Try this and report your results. We can figure this out.