No Crank Condition when Hot 2002 Liberty 3.7

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bendix

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Hello all,

So I have a 2002 Liberty 2wd 3.7 Automatic.

I've been having issues with a no crank condition when the jeep is hot. It could be from driving or from the ambient temp in the air, when it gets warm enough it doesn't crank. It won't even try to turn over. Apparently I'm not the only one who has experienced this from what I've seen online. There seems to be a variety of causes.

When I first got it, after not being able to find a solution I ran a fused, push button start to the starter. That worked great. when it didn't want to crank, I turned the key and hit the button and it started. Now that doesn't work.

I had a code for the Neutral Safety Switch so I replaced the Solenoid Pack in the transmission. That cleared the code but it is still not cranking when hot, although it did seem to help briefly. No more codes are showing.

The starter solenoid is getting 12v.

I think I may have narrowed down a clue. The Starter Relay 15A fuse when cold shows around 11v. When the vehicle is hot and won't start, it's only reading .35 (it varies).

Could this be caused by a bad starter switch or possibly a frayed or loose wire coming from the ignition switch?

I appreciate any advice!
 
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bendix

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Thanks for the reply,

I will check them and see if I can find anything.
 

Billwill

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If fuse #28 inside the cabin is not showing +12 volts when turning the key then you may have a loose connection or more likely I believe it is because your ignition switch is not working properly due to the famous "Actuator Pin Assembly Breaking" problem as Fuse #28 gets its power directly from the ignition switch.

First through try starting in Park instead of Neutral.

This is a well documented problem regarding the Actuator Assembly...should be lots of search results here or on other KJ Forums but basically you need to remove the plastic covers around the steering column...two female Torx screws. Remove the Ignition switch assembly off the steering column....one smaller Torx screw. Older KJs use a normal female Torx screw here while newer KJs use a Security Torx screw.

As you remove the ignition switch watch out for pieces of plastic or metal falling off...this means a broken Actuator Pin Assembly. You can test the actual ignition switch by putting the Jeep in Park or Neutral and with the key in ignition slot to unlock steering lock and enable SKIS anti theft if fitted....turn the ignition switch with a small flat screwdriver...the engine should turn over and you can drive like this while waiting for parts.

The Dealers do not supply the Actuator Pin assembly...most owners use a Dorfman replacement.
 

bendix

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Thanks,

I took the actuator pin out a while back and it is not broken.

It will start in park and neutral only.

I'll check #28.
 

bendix

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#28 is a spare fuse slot on mine, which fuse were you referring to?
 

bendix

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8 is also a spare. This is what my doorjamb fuse panel looks like.

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I'm thinking 36 is the ignition/run start fuse and just now it seem to have around 13v even when the jeep won't crank.
 
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JeepinJarhead03

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sorry i typed two different sentences / two different thoughts

F8 is a 40 under the hood if im not mistaken its between the starter and the relay according to the wiring diagram, or atleast on the path to the starter with the ignition initialized, here's the starter relay continuity check logic chain if that helps
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it looks like you're on the right track you just need the relay to point you and i've got a migraine atm and cant really read, it took me about 45 mins to dig this out

just incase you don't have it handy so you can catch which direction the fault is pointing
 
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JeepinJarhead03

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just wondering if the ohms on the relay even perhaps cold will show as being off
i just think you're on to something with the voltage discrepancy for a cold reading of 11v
 

bendix

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Thank you for taking the time to find that, I really appreciate it.

I hope I am on the right track too. I will get it figured out one way or another. Luckily it isn't my only mode of transportation. It will probably be a few days before I can work on it again but I will keep you all updated.
 
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bendix

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So I went to check the ignitin switch itself and the igntion switch actuator pin that was previously not broken (and the jeep was having issues when it was in tact) is now broken!

I guess turning the ignition too many times trying to diagnose it caused it to break, what a terrible design. I ordered a new one, hopefully it was actually the Solenoid Pack (NSS is incorported) that actually was causing the no crank condition when hot. We will see. I'll replace the actuator and report back.
 
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bendix

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Ok, I may be premature in saying this but I think the Jeep is fixed.

So, what I think happened is the solenoid pack (NSS) was bad and causing the hot start issue. Also at some point since I've been trying to fix the Jeep the ignition switch actuator also failed. Early on I took it out and it was fine. Over time trying to diagnose the jeep and turning that ignition hundreds or thousands of times (perhaps a little harder than normal when it wouldn't start), it finally broke. That confused the repair since I considered it to be ruled out.

Anyway, it's running good and cranking every time so far today, so I think we may have a victory!

As a side note, the Dorman camshaft sensor I installed during this process went bad today test driving it. I installed the OEM one back in it and the CEL went off and the code went away. I will not be buying aftermarket sensors again.

Thanks to everyone for your help, hopefully it is now fixed. Time will tell.
 

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