:: XJ No Crank Mystery HELP! ::

My 99 4.0 manual XJ wont crank. Repeatable Symptom 100% of the time:

I put the key in the ignition, turn to "on", all gauges work, headlights light up fine, fuel pump turns on, etc...
When i turn the ignition key to "start" i hear a faint "click" and then all the gauges go out along with the headlights, etc... As though something has shorted. I then can not even get the gauges to light up, i must unhook the positive battery cable and reconnect to even get the ignition switch to show any sign of life.

I have replaced the battery and the starter. no luck.

I have checked the starter relays and the fuses in the PDC and the interior fuse box.

When i turn the key to "on" and then jump the starter motor, the system shorts, same as if i turned the key to start.

My thinking has me ruling OUT the battery, starter, starter relay, ignition switch, clutch interlock switch.

I have a manual so no neutral safety switch.

It feels like it must be a grounding issue, though the jeep was running fine and then i got this issue have not found a fix.

WHAT COULD IT BE??
please help, this is a daily driver and i am so stumped!
thanks! -bigc

Turn the key on and jump it across the starter solenoid and see if it cranks

dirteexj94 said:

Turn the key on and jump it across the starter solenoid and see if it cranks

Click to expand...

Did this. does not crank. Creates same issue. Gauges short. no power to anything. I can hear the solenoid engage at the starter but does not even attempt to crank

when i remove the small starter relay in the interior fuze box (not allowing power to the starter at all) and turn the key to the start position, the ac blower and radio shuts off (as it should) and the gauges stay on (as they should). so i am assuming it is not the ignition switch or the clutch interlock switch

My guess would be that there is an electrical problem somewhere in the battery primary system,...could be the battery positive but my guess would be the battery negative. Start by removing and cleaning all cables at both ends if the cable, inspect for corrosion and replace as necessary.

You indicated you jumped across the starter solenoid. Was this at the starter itself or was it in the relay/fuse (PDM) box?

If the test was done at the PDM itself would indicate something is wrong between the battery and the PDM. If it is under the engine at the starter then the first things to look at would be both battery cables end to end.

Just had a similar issue with my 98, 4.0, ax-15. Think you are on the track to finding the problem. I would agree with techno, bad ground could be throwing things off. I know it is from an other forum, but I found this write up to be help. http://www.jeepforum.com/forum/f11/no-start-checklist-1449387/
Are you sure the starter is good. I had a duralast reman, that only lasted a week before it had me stranded (vatozone). Threw a new one in and after adding a push button I was on my way. I would suggest getting a voltmeter and looking for ground faults. I installed heavy duty mains in my engine bay years ago, but if memory serves me the rear block to fire wall and I think the dipstick tube? might be places to look. Also might be a good idea to have a load test done to the battery to rule that out as a cause as well. I have learned over the years with these rigs that NEW, does not all ways mean working.
edit; might want to take a look at the fuseable link on the main line to be sure it has not partially fried. I had one burn up on my old 88 and it caused a bunch of problems,

Check battery for proper volts. Check terminal conectors for corosion. Start with easy low cost things. All the while testing every thing you can. This may take longer but be cheeper in the long run. You will also gain much experience with the systems.

Check your battery cables, my motorhome would do this and i found my Pos cable was bad.

You may not have a park/neutral safety switch, but do have a clutch pedal position switch. Have you verified this?

looking at the wiring diagram, the clutch pedal position switch feeds the starter relay in the power distribution center. So I would first determine if you are getting power from the switch to control the relay.

scottmcneal said:

Check your battery cables, my motorhome would do this and i found my Pos cable was bad.

Click to expand...

My 85 XJ 5 speed is as basic as it gets, so it's not much of a parallel to the 99 XJ, but first year I had it the battery cables went. It look like I had power then either refuse to crank or act like it shorted out with no power to anything . Replaced a lot of parts before finally getting to the battery cables.

Edit. There isn't alarm system is there?
Had a Toyota with a starting problem turned out to the previous owner had an after market alarm they pulled out and never rewired it correctly.