I had just replaced my a/c compressor and serpentine belt after a few month of not driving my jeep. I had my battery on a trickle charge overnight to make sure I had battery power. So, I slid the key in and gave it a turn and got nothing. All power, lights, headlights , radio, fan are getting full battery power but there is nothing as I turn the key. I then grabbed a long screwdriver and jumped the starter to see if that was working. My jeep started right up. I got back in the drivers seat, let it run for a few minutes and then turned the key backward. Again, tried the key and got nada.

Could this be the ignition switch? Or could this be something else? My fuses look good. Is there some kind of module between the ignition and the distributor?

One other point. As I turn the key full forward I hear the sound of the small fuse or solenoid in the dash make a clicking noise. That sounds like it is sending a current but its not going beyond that...

Any idea are welcome.

Cherokee sport 4.0

 

did you check the starter relay

 

Try starting it in Neutral. If it starts more then likely your NSS (Neutral Safety Switch) is either needs adjusting, cleaning or needs to be replaced.

 

Good things to consider above. Here is more on how to refurbish the "neutral safety switch". It's a very common failure on the Jeep 4.0 engine.

http://bc4x4.com/tech/2010/jeep-neut...ty-switch-nss/

 

Thanks for the responses.

Nope, my jeep does not start in neutral. That was one of the first things I tried. I forgot to mention that.

Not sure where to find the starter relay, so I will look into that. I've read other posts the link this to a bad ignition, but as I mentioned, I hear power going to something when I turn the key.

 

I would check the CPS as well. Sometimes they work intermittently and you just got lucky when you jumped the starter

 

The starter relay is in the PDC under the hood. Top left relay, closest to the fender.

 

Well, I swapped out the relay in the fuse box with one of the other relays. No change. Will take another look this afternoon.

There's a black device mounted to the engine just in front of the distributor. On fat wire goes to the center of the dist cap. Would that be a source of the problem?

 

Would the CPS disable ignition completely? I thought a faulty CPS indicator was cranking but no start.

 

Ignition Coil
You are correct. A bad CPS will let it crank but no start.

 

Jeep starters are great but all power to the starting solenoid has to go true the starter brushes to work. It's very (very) common to see those fail because the brushes are either worn, oily or just corroded. It's an easy change or clean. Take off starter, remove back cover, remove brushes, clean rotating electrical contact part with fine Sandpaper and install new or still useable brushes. It's normal to have one a lot more worn out than the others. If so, replace the whole brush pack.

 

Ok, so I replaced the starter. The solenoid was burnt, the cables were corroded. However I still have no crank.....

Wtf. Battery is at 90%. I am really baffled.

 

OK. When I use words like Baffled I think to myself " back to basicss"

Battery is ok with voltmeter but if you measure voltage on the connectors of the battery (not the terminal themself) see if the voltage goes down or not. If there is a difference in voltage then from the terminals.. clean them.
Next test> Run a wire from battery positive terminal to the little screw on the starter (green wire). It should crank. if starter is new and you can make it run off the vehicle with booster cables but not that way, there is an other problem. Most likely a bad ground. The ground for the block is by the dip stick retaining bracket. good connection shall be clean. Clean clean ALL connections.
NOTE: %99 of electrical problems are bad grounds somewhere

 

Decided to jumped the new starter to let engine run till hot. Re- started the engine with the key. Lo and behold, my jeep roared to life.

So, seems the starter plus possible condensation in the wiring that accumulated in the past four months just sitting in the elements had kept the jeep from starting. Letting it run and get hot may have dried any damp connections? A loose assumption, but my jeep is back in service.

Thanks to all that gave me insights!

Nofo

 

[QUOTE=karl4x4;2480971]OK. When I use words like Baffled I think to myself " back to basicss"

True this. Wires between starter and solenoid and battery to solenoid were corroded. They were hidden by the plastic covering.

Thanks.