My '04 TJ won't start....most of the time

[RobP]

I'm new here and apologize for starting out with a technical question. I enjoy doing my own work on my Jeep but I am admittedly a horrible troubleshooter:redface: and can't figure this one out:???:. When I turn the key to the on position, the dashboard lights come on but the gauges jump around like crazy. When I turn it to the start position, there is nothing but a very slight hum, which doesn't seem loud enough to be the starter. It's pretty random but occaisionally, maybe once out of every 10-15 tries, it does start right up like nothing is wrong and it may do that 2-3 times in a row but then nothing again:x. It first started happening after sitting for about 5 days. Any advice on this would be greatly appreciated. Thanks!

 

[JPNinPA]

Measure the voltage at the solenoid key off and on. Voltage at starter. If both read battery voltage when they should get the starter load tested. If no voltage at the solenoid key on it may be the ignition switch.

 

[72rtchallenger]

I'm new here and apologize for starting out with a technical question. I enjoy doing my own work on my Jeep but I am admittedly a horrible troubleshooter:redface: and can't figure this one out:???:. When I turn the key to the on position, the dashboard lights come on but the gauges jump around like crazy. When I turn it to the start position, there is nothing but a very slight hum, which doesn't seem loud enough to be the starter. It's pretty random but occaisionally, maybe once out of every 10-15 tries, it does start right up like nothing is wrong and it may do that 2-3 times in a row but then nothing again:x. It first started happening after sitting for about 5 days. Any advice on this would be greatly appreciated. Thanks!

have heard maybe computer can do this,,try this from post I have read turn the key on untill all dash lights function normally and then see if it will crank an start , after it warms up it may start easily , I have read that the capacitors fail in the computer untill warm and this could be your problem , at least its something to try as I dont knnow much about the new ones , there is also the crank sensor which can cause intermediate starting untill it wont start

 

[69jeepcj]

Not the best with newer jeep either but I would guess the crank sensor. My dad had a car that did what you dicribe and it was his crank sensor. It didnt seem to affect his gauges like yours but the no start and humming match his symptoms.

 

[RobP]

Thanks for the advice, everyone. I'm definitely planning on checking all of this but unfortunately, or fortunately depending on how you look at it, it has started and run just fine for the past 2 days. The only thing that I did to it was pull the starter relay and put the same one back in. I know that relays can sometimes act weird when they are starting to go so I'm wondering now if that's all it is. The only strange thing is that the starter relay was the only one I touched and the clock reset itself to 1200 which would definitely point toward some kind of electrical issue. I'm just not sure if the clock reset before, during, or after pulling that relay. Thanks everyone!!!!

 

[72rtchallenger]

its possible your were dealing with a weak ground , if I were you I would clean more of the grounding points like battery cables on both ends and any other areas related to it,,you might be lucky and it was just a ground issue as this can cause similar problems as you described , I hope that was your main problem as it was an easy fix