KJ cut out while starting, now won't start at all

[AVR2]

Went to start my 2005 KJ, and it seemed to start OK - it cranked for about a quarter of a second. Then the engine just stopped. Now when I turn the key, I get the dash lights, but nothing else - no clicking solenoid, nothing. It won't start in neutral either.

Battery shows 12.6V and the posts and contacts are shiny clean and re-tightened. I've checked all the fuses and relays.

I guess it could be any of a dozen different things, right? There are no codes (naturally), so no clues at all.

 

[AVR2]

I just jumped between pins 30 and 87 on the starter relay, and the starter turned. I put the relay back in, and the Jeep started on the key. Turned it off, turned it back on again, and it started again.

We'll see what happens tomorrow morning, but does anyone have any suggestions as to what might have caused this?

 

[Hedsic]

Did you try hitting the steering wheel? Works for Deloreans

 

[Porkchop]

12.6 is low for the battery.

 

[bassmanbob]

12.6 is low for the battery.

This individual is correct, check the acid levels of the battery and see if you're low. If not, may be time to go get a new battery.

 

[AVR2]

Seriously? 12.6V is low? I've had low-battery starting problems before, but I still got a response from the starter motor with much less voltage than that.

Anyway, this morning it wouldn't start. Jumped the relay and it started. Got to work, turned it off, tried to turn it back on, got about a quarter-second crank and it stopped. Now it won't even start by jumping the relay, so it's been towed into the shop. I just don't have the time to run this one down myself right now.

 

[Billwill]

Seriously? 12.6V is low? I've had low-battery starting problems before, but I still got a response from the starter motor with much less voltage than that.

Anyway, this morning it wouldn't start. Jumped the relay and it started. Got to work, turned it off, tried to turn it back on, got about a quarter-second crank and it stopped. Now it won't even start by jumping the relay, so it's been towed into the shop. I just don't have the time to run this one down myself right now.

Nothing wrong with 12.6 volts on the battery with ignition off....if it drops below 9 volts while cranking then the battery is bad. Should read around 13.5 volts while engine running.

Jumping pins 30 and 87 in the Starter Relay does three things:

It isolates a bad Starter Relay.

It overides the ignition switch completely....you may have a bad ignition switch or more common is the Actuator Pin Assembly... that turns the ignition switch has broken....only available from places other than the Jeep Agents.

It overides the the interlocks to stop the starter relay energizing...these are the Park and Neutral interlocks for automatics and the Clutch Overide Switch for manual KJs.


You may have blown fuse 8 (40 Amps) in the power distribution box where the starter relay is located while jumping the pins....this fuse kills everything on the starter!

If the engine does turn over but not start then consider swapping out the ASD relay!

 

[Porkchop]

You might want to check in to it a little better but 12.6V is LOW for a battery. Now is that the problem with the Jeep could be could not but I would get that battery load tested.

 

[AVR2]

You might want to check in to it a little better but 12.6V is LOW for a battery

I've never heard that before, at least not when talking about a battery with the ignition off. In fact, all the information that I've ever read says that 12.6V with ignition off indicates that the battery is fully charged, and that a KJ battery should read 12.25 to 12.5V to be sure that it will crank properly.

Obviously, with the engine running the battery should be reading anything from 13.2-14.8V.

 

[Hedsic]

I thought around 12.6 was a full charge.

 

[Porkchop]

12.6 is the minimum to be at 100 percent 12.4 would be 90 percent and so on a good 12 battery should be 12.6+ and the best way to test it would be a load test. I guess if at a full charge your at 12.6 and you let it set 24hrs then take a volt reading it could give you and indication of how the batter is.

 

[AVR2]

Shop just called, it's the starter motor.