Help! 04 Cherokee issues

[OLDNEWBIE]

Even youtube can't help me on this one, any 04 Cherokee owners solved this issue??

I inherited an 04 Jeep Grand Cherokee 6cyl automatic with 50,000 miles. It has intermitent no crank problems.

Replaced the Neutral safety switch that was a screw in plug thing with a plunger and three terminals, no help. Has a new fully charged battery.

When problem occurs I can put the ignition key to on and pull a fuse/relay at the fusebox and touch a jumper wire there to start.

So its not the starter because that works every time. About to rig some sort of start button from fuse box to cab soon and call it done!

Any Ideas? I'm no mechanic but was a pretty good parts changer in the Army at one time.

[Quavodus]

What you said about the start button. I had to rig up a truck I had years ago like that. I wish I could tell you how to solve your problem.

[Photoguy67]

I am not a mechanic, but possibly the ignition switch itself?

[peejman]

1 minute ago, Photoguy67 said:

I am not a mechanic, but possibly the ignition switch itself?

Yep. Sounds like a bad connection in the key switch. 

[OLDNEWBIE]

19 minutes ago, peejman said:

Yep. Sounds like a bad connection in the key switch. 

But if I have key in on position I can start it by jumper wire at fuse box....key has to be on. I guess key all the way clockwise to start is a different position than on/run though.

A possibility I guess.

That fuse/relay I pull to use the jumper wire...is that a fail or work part or do they get glitchy sometimes? I switched it out with another one that was from the same fuse box and the same age but maybe I should try a new one?

[peejman]

20 minutes ago, OLDNEWBIE said:

But if I have key in on position I can start it by jumper wire at fuse box....key has to be on. I guess key all the way clockwise to start is a different position than on/run though.

A possibility I guess.

That fuse/relay I pull to use the jumper wire...is that a fail or work part or do they get glitchy sometimes? I switched it out with another one that was from the same fuse box and the same age but maybe I should try a new one?

It's a modern Jeep so I'd consider it a rolling glitch...   I don't really know the details. Swapping common relays around will quickly confirm if it's the relay or not.  In this case, it sounds like not  

A wiring diagram would shed some light on whats supposed to happen when. 

[OLDNEWBIE]

11 minutes ago, peejman said:

It's a modern Jeep so I'd consider it a rolling glitch

That's what I'm starting to find out. Probably going to sell eventually but easier to sell if people dont have to get under hood to start it.

[Grayfox54]

Ah, electrical problems in modern vehicles.  First off, you need wiring diagrams and know how to read them. Tracing down electrical problems is a crap shoot. You might get lucky and find it right off OR it could take days of fussin' and cussin' to find the problem. It could be any number of things. The ignition switch, the relay, the starter or just maybe its a tiny burnt connection or wire buried somewhere in the wiring harness. Believe me, these things can drive you absolutely nuts! 

I'd suggest replacing that relay you jump and see what happens. If that doesn't fix the problem, take it to a really good mechanic who knows what he's doing. Trust me on this. It'll be worth the money spent. 

[OLDNEWBIE]

Update....

Pulled the ignition switch, plastic box on left side of steering column opposite of ignition key. I jumped two random holes in the harness I disconnected and it cranked!

Thinking its that plastic box ignition switch wore out or the the keyed part of the ignition not activating the switch properly. The keyed part has a shaft and plactic pin the turns and pushes where it fits into the ignition switch.

 Ignition switch is a $30 part. Ill try that first......Actually 2nd as I replaced neutral safety switch already.

Reminds me of my Army parts changer days... Seems like sometimes we kept changing parts till it fixed the problem. Uncle Sam has deep pockets though.   

Edited April 19, 2019 by OLDNEWBIE

[RED333]

3 hours ago, OLDNEWBIE said:

Seems like sometimes we kept changing parts till it fixed the problem.

and it was the last part that fixed it, to bad I could never change the last part first.

[gregintenn]

1 minute ago, RED333 said:

and it was the last part that fixed it, to bad I could never change the last part first.

Where's the fun in that?

[Photoguy67]

2 hours ago, RED333 said:

and it was the last part that fixed it, to bad I could never change the last part first.

But then wouldn't that make it also the last part?

 

[Chucktshoes]

1 hour ago, Photoguy67 said:

But then wouldn't that make it also the last part?

 

Exactly! I mean if it was the first part, why would you keep swapping parts?

[gary_boom]

18 hours ago, OLDNEWBIE said:

Even youtube can't help me on this one, any 04 Cherokee owners solved this issue??

I inherited an 04 Jeep Grand Cherokee 6cyl automatic with 50,000 miles. It has intermitent no crank problems.

Replaced the Neutral safety switch that was a screw in plug thing with a plunger and three terminals, no help. Has a new fully charged battery.

When problem occurs I can put the ignition key to on and pull a fuse/relay at the fusebox and touch a jumper wire there to start.

So its not the starter because that works every time. About to rig some sort of start button from fuse box to cab soon and call it done!

Any Ideas? I'm no mechanic but was a pretty good parts changer in the Army at one time.

I have been a mechanic for over 40 years and parts changing is how it’s done now.

[A.J. Holst]

3 hours ago, gary_boom said:

I have been a mechanic for over 40 years and parts changing is how it’s done now.

While Gary can actually mechanic a vehicle, most parts (modules) are designed to be replaced vs. repaired.

Sealed units with rivets and gorilla adhesives, no bolts or screws...

Can you even get new brushes or have an alternator rebuilt these days?

[peejman]

1 hour ago, A.J. Holst said:

While Gary can actually mechanic a vehicle, most parts (modules) are designed to be replaced vs. repaired.

Sealed units with rivets and gorilla adhesives, no bolts or screws...

Can you even get new brushes or have an alternator rebuilt these days?

There's no incintive for a mechanic to fix parts today. They're pushed to flip cars as fast as possible and to replace parts that might not have needed it because of how the business is structured... 

[1fast4by]

Intermittent crank no start on a 4.0 Jeep...

 

Crank shaft position sensor.

 

I have been in the auto service industry my entire life, ASE Master certified with L1 for over a decade.

 

Now, Obviously Internet diag is impossible, and I wont promise you that is the fix... But it is very much an educated guess.

Edited April 20, 2019 by 1fast4by

[OLDNEWBIE]

11 minutes ago, 1fast4by said:

Intermittent crank no start on a 4.0 Jeep...

 

Crank shaft position sensor.

 

I have been in the auto service industry my entire life, ASE Master certified with L1 for over a decade.

 

Now, Obviously Internet diag is impossible, and I wont promise you that is the fix... But it is very much an educated guess.

Intermittent no crank this time around.....but I'm sure that sensor is in my future as well.

Taking a break from it today other than maybe shopping around online for cheapest ignition switch I can find. I took the old one apart as best I could and cleaned, adjusted and fiddled with the contacts as best I could then reinstalled. No luck. pretty convinced it's that part or the PITA to change keyed part and shaft.

[OLDNEWBIE]

Update...

Gambled more dough on the switch.

Switch no fix.

Rigged up a start button for now,  works great except for 46 seconds of a warning beep to warn against key in ignition at start up.

[mikegideon]

On 4/19/2019 at 9:42 AM, OLDNEWBIE said:

Even youtube can't help me on this one, any 04 Cherokee owners solved this issue??

I inherited an 04 Jeep Grand Cherokee 6cyl automatic with 50,000 miles. It has intermitent no crank problems.

Replaced the Neutral safety switch that was a screw in plug thing with a plunger and three terminals, no help. Has a new fully charged battery.

When problem occurs I can put the ignition key to on and pull a fuse/relay at the fusebox and touch a jumper wire there to start.

So its not the starter because that works every time. About to rig some sort of start button from fuse box to cab soon and call it done!

Any Ideas? I'm no mechanic but was a pretty good parts changer in the Army at one time.

I fixed Jeep two weeks ago. Starter relay. I swapped it with a wiper relay just to get the truck to start. I just followed a Youtube video. Not the exact year. It's in a plastic box under the hood with some other plug in relays. Looks like a fuse box. That may not be it on yours, but it fixed this one. The relays are black plastic, maybe 1/" x 3/4". They have replacements at the auto zone.

[OLDNEWBIE]

I tried swapping the relays with same type in fuse box. Maybe should have bought a new one and tried as all of them are original to car.

[mikegideon]

24 minutes ago, OLDNEWBIE said:

I tried swapping the relays with same type in fuse box. Maybe should have bought a new one and tried as all of them are original to car.

A swap should have done it. On the one I fixed, the starter was a known problem. Those things should last forever.

[Capbyrd]

On 4/20/2019 at 12:39 AM, Chucktshoes said:

Exactly! I mean if it was the first part, why would you keep swapping parts?

Boredom. 

 

[dralarms]

On 4/19/2019 at 10:42 AM, OLDNEWBIE said:

Even youtube can't help me on this one, any 04 Cherokee owners solved this issue??

I inherited an 04 Jeep Grand Cherokee 6cyl automatic with 50,000 miles. It has intermitent no crank problems.

Replaced the Neutral safety switch that was a screw in plug thing with a plunger and three terminals, no help. Has a new fully charged battery.

When problem occurs I can put the ignition key to on and pull a fuse/relay at the fusebox and touch a jumper wire there to start.

So its not the starter because that works every time. About to rig some sort of start button from fuse box to cab soon and call it done!

Any Ideas? I'm no mechanic but was a pretty good parts changer in the Army at one time.

I’ve been through this, turn the switch on and no crank, won’t even turn over. Turned out to be the pcm fuse bad. 

[RED333]

If you have and can read a volt meter check for 12 volts to "T40 12 BR" at "C165 on #2" when you try to start and have no start. Let us know what you get in volts.