1988 XJ will not turn over

I have a 1988 XJ, 4.0L/AW4 that will not turn over. It used to do this every once in a while where you would turn the key and nothing would happen but you would try agin and it would start. Well, recently I swapped out the transmission and forgot to unhook the battery and tapped the starter against the body causeing it to spark. After the Jeep was back together it would not fire. When you turn the key it does not turn over but the gas gauge goes up and the radio and clock turn off. I checked the fuse box and swapped out the starter, still nothing. I started swapping around the blue relays under the hood, moved around some wires and tried it. It started. Later that day it started fine then later would not start again. I have since checked all the grounds, replaced all 4 of the blue relays, replaced all the fuseable links going to the starter relay, replaced the starter relay, looked in the harness for loose wires, and even replaced the wire going to the starter solinoid.

First off, which of the 4 blue relays have to do with ignition/starter?

Second, does anyone have any ideas of what to check next?

I am guessing that due to the gas gauge going up and the radio/clock turning off that something is grounding out but I can't locate it?

Could it have to do with the actual ignition switch it's self?

Any help would be appreciated.

Just thought I would add that the starter is getting 12v constant but the solenoid is getting nothing with the key turned.

Do a little search for "NSS" or Neutral safety switch.

x2, I'd start there.

make sure your grounds are clean also.

NHscrambler said:

Just thought I would add that the starter is getting 12v constant but the solenoid is getting nothing with the key turned.

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You need a new starter solenoid.
It's easy enough to check:
With key off,
1) Get someone you trust to help for a minute.
2) Get 6' or so of power wire, stripped a bit on each end.
3) Feed the wire from the pass. side of engine bay down to near the starter.
4) From underneath, hold the wire end to the solenoid post (don't touch exposed end)
5) Have trusted assistant touch the other end to B+(don't let asst. touch exposed end).
If she cranks, it's the solenoid.
Leaving the key in the OFF position will prevent fuel delivery and keep the engine from actually starting. MAKE SURE THE TRANNY IS IN PARK! Chock the wheels too, just in case.

You will have to drop the starter to change the solenoid. It's held to the starter by 2 screws(phillips), one of which is blocked by the tranny. Kinda PITA. You'll need a 14mm and a 15mm socket for the starter mounting bolts and an 8mm one for the starter relay wire. When I did mine last week, I also needed a 1/2" and a 9/16" to get the the other two connectors off, but both were 1/2" on the new one. An 8" wobble extension helped a lot.

kujito said:

You need a new starter solenoid.

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as he's not getting power to the solenoid, I'd say it's NOT the solenoid that's the problem. More than likely NSS or starter relay.

IIRC, it is not unusual , on older vehicles,for the guages to drop out in start position.

I think the arcing against the starter is a red herring.

It does sound like a bad/dirty gear selector switch. You just had the tranny out? Is the selector switch on the right side of the transmission plugged in? I know that sounds stupid, but...

If it is attached, try starting it in N instead of P. If that does not work, hold the key in Start, hold the shifter lockout button in and move the shifter back and forth "around" neutral. I've gotten my Jeep going after a wet winter run that way.

Well, thanks for all the ideas everyone. I have figured out the problem doing what
Zuki-Ron suggested.

Zuki-Ron said:

If it is attached, try starting it in N instead of P. If that does not work, hold the key in Start, hold the shifter lockout button in and move the shifter back and forth "around" neutral. I've gotten my Jeep going after a wet winter run that way.

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I tried this and it didn't work. So I held the key and just started moving the shifter through the gears. It caught while doing this so I tried each gear. BINGO when I put it in "R" the Jeep started. For some reason the shifter cable was WAY out of adjustment for the new transmission. I am not sure if maybe the shifter arm is a bit bent or positioned differently because the shift selector was off a full position. So "P" was reverse and "N" was 3rd.