Sorry for the generic title, I have a 1994 Grand Cherokee Laredo that won't start. It has not had a problem until this morning.

This morning it started fine. Drove it about 15 minutes stopped and turned it off. Came out 10 minutes later and it would not start. There was clicking but not starting. Hooked up jumper cables and it started. Drove to another location and it sat for about 1-2 hours, came out and it started. Drove to another location where it sat for a few minutes and it would not start. Tried jumpers and it would not start. Let it sit for a while and it still won't start with jumpers. All of the dashboard lights come on. I did the DTC thing with the key/CEL and got 12, 55.

Any suggestions?

 

On the last attempt to start, did it turn over, or just click?

If it just clicked, have your alternator and battery checked. Check all fuses and relays related to the charging system. Almost seems like the alternator is failing, just not enough to kill it during driving. Is there any corrosion on the battery terminals?

 

I also thought it might be the alternator, but I ruled that out when it would not start after 15 minutes of being connected to another car (with the engine running effectively charging the battery).

The battery was just replaced last year.

But the story gets crazier. Went back about 30 minutes ago and it started. Drove 10 minutes, parked, turned it off. Tried to start it again....and....it started.

 

Now THAT sounds like a bad connection. Check your starter wires. Check for any corrosion around the terminals. Try to check any point where the starter wires touch any surface and check for fraying. If that doesn't fix the issue, you might have a bad starter solenoid (MAYBE).

 

I did replace those last Fall, but will check them when I get a chance. The car is in my daughter's possession at school (3+ hours away) so this is all a remote diagnostic thing.

For now it has made its way back to her apartment parking lot where it will sit until I get there next week.

Thank you for your help. I am thinking about getting the battery/alternator tested. Aside from that do you think there are any other possible causes? crankshaft sensor, PCM, etc.?

 

With an intermittent problem like you are having it could be a lot of things. I once had a Town & Country that had a bad crank sensor, but it died while driving (previous mechanic striped the cam AND crank sensor bolts... LOL).

But with that aside It really seems to be a connection issue from what you tell me, especially since after it starts there are no issues. Be sure to take a multimeter with you and check resistances and crossrefrence the data with OEM specs. I think the worst you will be looking at is a bad starter solenoid or the starter itself, but I could be wrong. Hard to tell specifically if you don't have the Jeep in front of you.


Wishing you the best of luck!

 

Thank you. I did forget to mention that I also replaced the starter last year.

It is funny if this is a connection problem because I was thinking of having her tap the battery terminals with a hammer (she has one to that she could unstick the starter before i replaced it) but I didn't because it just did not appear to me to be the cause due to the prolonged period which it would not start.

 

DO NOT have her do this (lol), but when you get there try and have the no start issue occur, then jump the solenoid terminals. If it starts, its the solenoid. I asked but didn't get an answer, so I'll ask it again so I can be sure. THE LAST TIME she tried to start when it was on jumpers for a while, did it click or did nothing happen?

 

I used that trick (last resort) when the started failed last year.

There was a clicking sound which is why I figured it may not be the battery connection.

I have not looked under the hood since the fall but the battery terminals may be corroded enough where the connection is intermittent.

 

Yeah, the more i hear about the problem the more I think it's just a connection. Clicking means a couple of things:

A: Not enough power from battery, either from low battery or bad connection, solenoid engages starter, starter does not have enough amperage to turn starter which pulls down battery, deactivating solenoid, breaking circuit, making enough power to activate solenoid again. This cycle repeats over and over. REPETITIVE CLICKING

B: Solenoid gets power to start, but then malfunctions (either has a short or gets too hot, those 2 mostly go hand in hand) and deactivates. This cycle repeats over and over. REPETITIVE CLICKING

C: Solenoid closes circuit and energizes starter, starter gives one KNOCK or CLICK noise, then nothing. This is a sign of a bad starter (internals seized either from bad bearing, starter gear stuck, of magnets in starter broken). SINGLE KNOCK OR CLICK

This is about all I can give you to check. I hope this helps you out.

And I probably screwed up with the electrical terminology, but I hope you get the point