2006 4.0 has no crank, no start, and no power to starter

Robmacdaddy

New Member
Joined
May 23, 2022
Messages
13
Location
Knoxville tn
Hi, I've read through the other starter issue post but nothing seems to directly address the issue I'm having. Put the key in turn it on dash lights come on turn the key to ignition to start you getting nothing no sound nothing at all no popping no clicking no whirling none of the obvious things you normally get. The only way the starter will turn over is to jump it from the solenoid to the hot wire from the battery. With the key on or off starter engages engine turns over sounds like it'll start but it won't fire. Does the same thing whether in park or neutral. I get 0 signal to the solenoid. I do have 12 volts on the starter from the battery. I checked these both by grounding test light and multimeter to the starter body so that ground is good. I unpluged the switch wiring harness from the switch and have power at the switch. on the left side of the switch I have power on the first second and 5th connectors and on the right side of the switch just power on the second connector. I've unplugged the wiring harness and inspected the connector under the left side of the dash all looks good when I did that all power went away from the switch. At the PDC 30 amp fuse in slot number 6 is good, 25 amp fuse in slot 22 is good, verify the relay was good by using a known good relay and in the starter relay slot I have power on number 30 or 3 but no power anywhere else on the relay. This was tested with the key in start mode. I'm assuming there should be power going out of the relay to the solenoid but I'm getting nothing. Could there be a break in The wire from the ignition switch to the relay? Is there a connector plug somewhere in that harness that could be burnt or melted causing the break. On my XJ I had that happen. Hotwire from the switch melted had to wire past the switch to make everything work again. I can't seem to find a connection point under the dash of the LJ except the ones on the left kick panel and they all look good. Thought I would ask for any help on tracing wires or any other suggestions. I will say the battery is good it's showing 12.4 volts and the fuses in the dash behind the glove box are all good. I have not tried a remote starter switch yet. Reason being is when I jumped it at the solenoid it wouldn't start and I'm thinking that the break is before the splice that goes to the PCM and then to the relay. If I'm wrong please tell me. I've looked at the wiring harness in the engine compartment and can't find where that splice is all I see are the four plugs that go into the PCM three come from the bundle that comes from under the dash and goes across the top of the firewall the other one out of slot three on the PCM goes down to looks like starter alternator that area. I have a fsm that I downloaded Sunday just haven't had time to dig into it yet.
 
Similar problem caused by bad starter module in the steering column. Another person had a similar problem and got it to start simply by plugging and unplugging the connector to the module apparently because of corrosion on the pins.
 
I seem to recall some oddity with the 05 and 06 key having to be in the start, not on, position even if you jump the starter for it to fire. If you have a helper, worth a shot.

Check the ignition actuator pin. Common failure point.

It can be started with a screwdriver if the actuator pin is the problem.
 
Already installed a new switch and actuator pin assembly. No change. Today I traced all wires from the switch to the PDC to check continuity. All were ok, no breaks. I did find that the purple/yellow wire on switch which makes the contact with actuator pin runs into the PCM but doesn't come back out but a brown and green wire comes out and goes to starter relay pin that would feed signal to solenoid. Going to test and trace more Tuesday... Thinking PCM could be bad not supplying signal to starter relay.thanks..rob
 
Here's the schematic. FSMs are available under resources.

Yeah, this is what I was remembering, PCM is involved in starting which complicates things.

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I had a similar problem with my Jeep about a month ago. Wouldnt start even though all other electrical components were fine. Was able to get it to start a couple times and it would die while driving. Ended up being bad PCM. I would check that and if it does end up being the problem then get one from WranglerFix. They have the best and most reliable replacement.