Patrick S. Kotyuk

Good afternoon everyone! Today I come to you because I have a no crank issue with my Cherokee and wanted to see if anyone has some advice or experience with this particular issue.

My XJ:
1990 Cherokee Laredo
4.0 2WD AW4

My Issue:
No Start/No Crank, when the car is hooked to battery power and the key is turned into run, or accessory, NO accessories come on. The power LOCKS work, as well as headlights, hazards/flashers and reverse and brake lights, as well as the interior vanity lights. The car also does not start. Their is no fuel pump prime when key is turned to RUN, there is no click or attempt at turning over.

What I've Tried:
Battery - Disconnected and cleaned ALL terminals and every single ground. I have attached the cables to another, running car's battery with the same results.
Neutral Safety Switch - Will not start in P, or N. Will not start when jiggled. Will not start when the B+C terminals on the NSS connector are jumped. Reverse lights are functional in the proper R gear.
Fuses - All visible fuses and fusible links APPEAR to be operational and not burnt out.
Starter - Relatively brand new, and is highly unlikely to be the issue given the other circumstances (No accessory power, etc.)
Fuel Pump - Also relatively brand news, and is highly unlikely given the other circumstances (No accessory power, etc.)
Spark - Unable to test due to no signal being directed to spark plugs.

When It Happened:
The only thing I can remember before it didn't start was when I was driving home, the jeep felt like it turned off or went out of gear for a moment. I was actually about to pull off to the side of the road but somehow the jeep was either okay to drive home or came back to life long enough for me to go home. After we parked and turned off, it hasn't started since.

I will happily send pictures or give any more information requested to get her back on the road. Thank you all!

fb97xj1

Ignition switch, maybe? Wiring and/or connections? Or something not right with the backside of the fuse box? Thats all i can think of atm.

Patrick S. Kotyuk

The ignition switch and something with the back of the fuse box are high on my list to checkout. If I understand correctly, there is some sort of bulkhead connector that attaches to the fuse box from behind?

RockyMtn96XJ

Excellent job on doing some homework first and getting some troubleshooting done instead of just getting on here and asking "why wont my jeep start?" I would have done what you did first also, so now its going to be fun trying to figure out the issue. I agree ignition switch and the associated wiring is a good place to go next.

What would be the appropriate check at the ignition switch be? Voltage from the battery or continuity of wires?

4.3L XJ

One thing you can do to trouble shoot is to turn the headlights on and then try to start. If they dim and nothing happens then you have insufficient power from the battery.

Patrick S. Kotyuk

Thanks! Unfortunately I have tried this, as well as directly hooking up to another running cars battery with identical results.

4.3L XJ

So did the lights dim, or just not start?

OK, so does your starter relay work. Swap in the AC relay and see what happens

Patrick S. Kotyuk

The key turn had no affect on the lights. I can test the starter relay, not too familiar with how it works but I have a Haynes I can reference. How do I swap in the AC relay?

RockyMtn96XJ

Take out the starter relay and set it aside, then take out the AC relay and put it in the starter relay place. in the correct orientation

4.3L XJ

I will be labeled in the power distribution center lid

Don X

If the accessories not working means the radio, wipers, poser seats, a/c fan, and the headlights,flashers, powers locks, all which don't need the key in the on or accessory position, work some things can be eliminated.

1. The battery is obviously eliminated because you have power.
2. The power to the fuse block is okay because (i) power for what is working, which comes through the fuse block, is getting to the working systems
3. Because power for the systems that aren't working have multiple fuses, the chances that you have blown all of the accessory fuses at once, without affecting the fuses for the systems that are working, is slim to none. Additionally, I don't think those fuses would cause a no crank problem because power to the solenoid doesn't go through the fuse block.
4. Because the accessories that aren't working go through the fuse block but the solenoid doesn't go through the fuse block and isn't cranking the starter, the problem isn't the fuses unless the accessory problem and no crank problem aren't related. I'm not willing to make that bet..

Based on that, if the power for the accessories isn't getting to the fuse block, and power isn't getting to the solenoid, I would surmise the problem is either power is not getting to the ignition switch or the ignition switch itself since power isn't going to either the fuse block or the solenoid. That's what I would be focusing on right now.

Don X

I also meant to add that it won't be a sensor because those don't affect the accessories.

RockyMtn96XJ

That first sentence was a little hard to follow, but what came after that was a little easier, and the very last statement is the one to key in on....

Don X

Yeah. I just reread that. Probably could have done better. Basically if the accessories that need the key to be on (radio, wipers, etc). do not work when the key is on but lights, locks, flashers, etc. do work with the key off, then some things can be eliminated as being the problem.

BruceB

remove and clean the connectors to the ECU/PCM....sounds like an intermittent connection or the start of failure of the ECM/PCM