Hey everyone,

I'm on my third XJ now, and I'm baffled at the current issue I'm having. I have a 2000 XJ 4.0 Sport AT. My XJ will start like normal, but if I leave it in Park or Neutral after starting it, the starter continues to try to turn, grinding on the flywheel. When we shift it into Reverse or Drive, the grinding goes away. I replied the ignition switch last week, and it ran for a few days without issue. After a few days of running without issue, the problem crept back up again. I'm looking into the Neutral Safety Switch as my next replacement, but I was hoping someone here has had the same issue and found some silly little AND CHEAP quick fix for it. Also, it seems like the NSS is operating as it should, given that the grinding goes away when I shift into a forward or reverse gear. Fortunately, the flywheel is still in good shape and the starter doesn't seem to have sustained any structural damage as a result of winding on the flywheel anytime we're in Neutral or Park.

Thanks in advance,
Steve

 

The NSS won't cause the starter to keep running. This sounds like a bad starter relay that's sticking. Located in the power center under the hood. Try swapping it with the a/c relay. They're under $10 for a replacement at the autostore.

 

Of course! A stuck relay. I’ll give that a shot when we get home.

 

So, I tried to swap the relays around and unfortunately that didn't solve the issue. Any other ideas?

 

You need to determine if this is an electrical problem or mechanical one.

Assuming the starter still disengages when you shift, start it but instead of shifting, pull the starter relay. This will break the circuit to the starter solenoid. If the starter disengages, you have an electrical problem and will likely need to break out the multimeter. I'd repeat this a few times to make sure.

If it doesn't, you have a starter issue. The Bendix drive is not retracting when the solenoid de-energizes. This can be due to a bad spring inside the starter, corrosion on the shaft or too tight an interference with the teeth on the starter and flex plate. I can only speculate in this case that the "shock" (mild as it is) of shifting into gear is enough to pop the bendix.

 

Hey!

Thanks for the direction. The starter disengages when I pull the relay. Do you have a particular place I should start with the multimeter?

This Jeep is a great mechanical runner. I’m hoping to resolve this issue and the other electrical issues that stemmed from the previous owner doing some shoddy wiring.

 

Cruiser54 (one of the mods here) has the FSM on his site.

https://cruiser54.com/?page_id=365

Grab it and review page 8W-21-3. That's the starting system.

 

When you look at it, Fuse 19 (10A) in the junction block feeds power to the coil side of the relay. You could try it again, but this time pull the fuse. That should help identify if the short is upstream or downstream of the fuse. The hot side of the fuse gets power from the ignition switch (page 8W-10-11) when the key is in START.

 

If pulling the relay stops it, then the next most likely culprit is the ignition switch which you said you replaced. Possible the key just isn't springing back to the run position?

 

With the quality of todays parts, I think it would be good to test that new switch. You would need a multimeter to check continuity to verify it is not connected after you let the key spring back. You could do it with a test light, even a test light you rigged up, but the meter would be easiest.

When I was still new to fixing, I called a friend with a stalled/won't start. I had verified fuel, but I was asking him how to know if it is coil or exciter before a I walked a long way to the parts store. He says, "Use a test light to check for the signal from the exciter." "I don't have a test light." I tell him. He says, "You are standing next to the car, you have a test light with you. Pull a tail light bulb and use a bit of the wire from the floor pan or trunk that we both know is lying loose down there." "Oh, right." Now I always make sure there is at least some 12ga wire in the vehicle to use as a test light or a field repair.

 

Novel idea to use a taillight bulb as a test light. I have a cheap harbor freight meter and some basic hand tools in the back

 

Personally, I would use a very thin wire to insert between the relay terminal that receives the 12V signal from the ignition key, and its female slot

This should only alight your test light when the ignition is turned to start. If it alights any other time, the problem is upstream from the relay

If the engine tries to start without that terminal energising, the problem is in the relay or downstream