Starter ok, battery, ok installed new starter relay and ECM. All the dash lights and other electronics turn on with the ignition. After the is driven and sits for a while, the car will not start. The following day the car will start. Totally baffled....anyone have any ideas?

 

Welcome! Just for future, there is a better section for your specific model

https://www.cherokeeforum.com/f1/ <--- this is the grand cherokee section.

What motor is in your Jeep? Is it the 4.0 inline 6 or the 4.7 v8?

 

I moved it

 

The engine is the 6 cylinder.

 

:Thumbsup:

Does the starter crank when you turn the key or does it do nothing at all?

 

Starter does not turn over. The only thing working is the dash board lights. Tried to start the engine in neutral, still wil not turn over.

 

That sounds like a neutral safety switch malfunction. On our models, I'd recommend taking it out and cleaning it, but your model has a different type of NSS....

 

NSS, in side of transmission just above the shift cable entry.

 

Tried this, but didn't work
Also tried starting in neutral. .still doesn't work. ..

 

Have you tested the switch or checked for power to it?

 

Yes, I have power to the starter and the ignition switch.

 

No, I'm talking about the NSS. You should only have power to the starter solenoid with the key in the start position. Try putting a jumper wire from the large terminal on the starter to the small one. The starter should crank the engine when you do that.

 

Weak or no crank when hot is almost always a bad starter. Not with this particular vehicle, but in general. The starter can test ok cold and fail when hot. Sometimes they totally fail soon after the first signs of issues, sometimes they work intermittently for weeks.

 

Okay, I remember carrying a hammer to tap on the starter to make it work! LOL!

 

My kid did this for months earlier this year. Broke up with his leech girlfriend, went to leave, car wouldn't start. took hours for a ride, and they made up while he was waiting.

There is a moral in there somewhere.