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Old 05-05-2017, 07:26 PM
Thread Starter
Join Date: Jul 2014
Posts: 3
jeep jk 12´wont crank

I have a jeep jk 12 with a lot of mods, trails and repairs. some days ago i disconnect the ecu, i connect back it again and everything fines. a week ago a try to turn on and it did not crank. its manual transmission so i turn on by pushing the car and once is running everything works perfectly. i call my electrical technician and we start with the battery, everything fines. The starter is perfect, the valve that work in the clutch to start the vehicle is working. Ok here came the tricky part.

When i turn the key everything work perfect, the lights, the a/c, etc. but when i do the second turn to crank all the gauges and lights in the cluster turn off, and then it came back, some sounds from the fuse box and the check engine light and the a/C light start flashing when i try more than twice. We check the fuse box and the starter relay is working good but is not receiving signal. I connect the diablo sport and no code is found.

My guess are, ecu locked, but a friend of mine expert in jeeps told me that ecu does not control the starter, and in any case the ecu was locked, it wont turn on by pushing it. So my second guesses are, ignition switch but when i turn the key the cluster shut off so is doing something, in that case can be the wiring from the ignition switch to the fuse box, but i hear a noise when I try to crank from the fuse box.

So by now i really want to spray the jeep with fuel and throw a lighter on it. im sure it will ignite really fast.

Please help me

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Old 05-07-2017, 11:53 AM   #2
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Everything goes through the Totally Integrated Power Module (TIPM). There have been problems with later model year JK's. The problems can be difficult to diagnose. Even dealers will give up and just replace it. I can't say that this is definitely your problem, but your issue seems to point in that direction. I would first make sure that all of the fuses are set correctly.

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Old 05-07-2017, 12:31 PM   #3
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Originally Posted by franqueichu View Post
I have a jeep jk 12
How old is the battery? The OEM batteries start to go after around 3 years. You are lucky if yours lasted this long. It may have enough power to turn on various lights and indicators but not enough to crank the engine.
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