Adam Rogers

I just got home from the store my 98 xj was driving just fine. I put it in park then all of a sudden it started to idle a bit high, so I turned off the engine then went to start it again to see if the high idle would go away, but then it wouldn't start. When I turn the key I hear the starter click and that's it. No crank at all.

Roler

Sudden failure is usually better to diagnose than intermittent (electrical) problems. It could be something relatively simple
Just to help you a bit on the way on the process:

You sure you were in Park or Neutral at the time of trying to start again? The Neutral Safety Switch sometimes plays up, preventing your car from starting. Moveit a bit back and forth and try starting it again. Or try and start in Neutral, assuming that you usually try starting in Park position.

Just hearing a click at the starter, usually means bad battery, NSS issue, the power is not getting to the starter or the starter itself would have a sudden failure (less likely)
Start with checking your connections, something might have come loose, is corroded, or making bad contact otherwise. Cables from the battery (check the connections there too, clean them up for good measure) all the way to the starter. It would mainly be the power side of things, since the starter grounds via where it bolts on to.

Do you have a multimeter? If so a quick voltage drop test will provide a lot of info for this.

A simple test to make some entry point in the diagnostic process is the following in a no-start-no-crank situation(after checking and cleaning up connections)

- make sure battery is fully charged (preferably have it load tested too, to take that out of the equation
- turn key to ON position
- under the hood: remove the starter relay from the PDC (little black plastic box near the righthand side fender that holds relays and fuses)
- jump pinsocket 30 and 87 (I can send a pic if you need help to identify these, but standing on the right side of the car looking at the sockets, its the ones on the 12 and 6 o'clock position)

See if it now cranks (or even starts)

This for starters (...), report back how this goes.

Adam Rogers

I really appreciate your feedback and your answer was actually very accurate the problem ended up being very simple the red wire from the starter to the battery popped out of the copper battery connector and last night I over looked it thinking it was something more complex like a sensor I feel really dumb but goes to show how important it is to start checking with the most basic things first!

Roler

Well glad to hear is was indeed the relatively simple cause.
And thanks for getting back, closure is good

Happy travels mate