No crank after engine install

[Daniel]

Hey guys, I know there's other similar forums out there for no cranks and such but I'm making one specifically for my issue. I've got a 2004 3.7 M/T Renegade. I had the engine out and all apart. I replaced pretty much every gasket and seal on the engine. I have the engine back in but when I went to crank it I got nothing. No clicks or anything. Also, my low end OBD2 scanner plugged into the DLC is "unable to establish communication." The starter works when I jump the relay. My thought is maybe I have a ground somewhere for the PCM that didn't get hooked back up right because it seems like the PCM is offline except it runs the fuel pump when I key the vehicle on. Swapped my starter relay and I know it's good. Swapped my ASD relay and I know that's good. Seems like my PCM just isn't powering the starter control circuit when I turn the key. I've got the grounds on the back of the heads hooked up and I know my block is grounded to my battery. I checked for ground continuity there. Thoughts?

 

[Billwill]

Remove the Starter Relay and with the Jeep in Neutral and Park briefly jumper pins 30 and 87 together inside the empty socket.....engine should turn over!

If it does now turn over you have a broken Actuator Assembly ie. the section that rotates when you turn the ignition key.

If not the above..using a Voltmeter check that the large terminal on the Starter Motor has +12 volts at all times with respect to the Starter Motor Body and that when you turn the ignition key check that the small terminal at the Starter motor ie. the Solenoid...receives +12 volts with respect to the Starter body!

After this you need to climb into the Wiring Diagrams with your Voltmeter!

 

[DadOSix]

Hey guy, I know there's other similar forums out there for no cranks and such but I'm making one specifically for my issue. I've got a 2004 3.7 M/T Renegade. I had the engine out and all apart. I replaced pretty much every gasket and seal on the engine. I have the engine back in but when I went to crank it I got nothing. No clicks or anything. Also, my low end OBD2 scanner plugged into the DLC is "unable to establish communication." The starter works when I jump the relay. My thought is maybe I have a ground somewhere for the PCM that didn't get hooked back up right because it seems like the PCM is offline except it runs the fuel pump when I key the vehicle on. Swapped my starter relay and I know it's good. Swapped my ASD relay and I know that's good. Seems like my PCM just isn't powering the starter control circuit when I turn the key. I've got the grounds on the back of the heads hooked up and I know my block is grounded to my battery. I checked for ground continuity there. Thoughts?

Ground straps from the firewall to the heads?

It is the one that looks like a big ‘v’

Just for kicks, try a jumper cable from the negative battery to someplace substantial on the block. That would be a big enough ground to test out the missing ground theory.

 

[Daniel]

I had jumped the starter relay and it turned over. I also jumped the terminals at the starter and it cranked too. Messed around with a couple other things I was putting back together and plugged in a different scanner and the scanner would communicated and the engine cranked with the key. Not sure what I messed with that made it start but it's working now with no issues. I guess if it comes up again I'll have to dig into it some more.

 

[DadOSix]

I had jumped the starter relay and it turned over. I also jumped the terminals at the starter and it cranked too. Messed around with a couple other things I was putting back together and plugged in a different scanner and the scanner would communicated and the engine cranked with the key. Not sure what I messed with that made it start but it's working now with no issues. I guess if it comes up again I'll have to dig into it some more.

I was suggesting chasing the ground path because you stated no comm with the pcm.

good to hear you got it running!

 

[Billwill]

It is Halloween time so the Gremlins are out and about messing us around!