No start, no crank, no power, rough idle, new battery, new starter, new IAC.....

[Joshua13]

2000 xj, automatic, 4.0l 315kms
Alright guys here is the ongoing sage of my jeep. I moved to a colder place a few months ago at which time i replaced the battery due to no start. She ran good for about a month, then had idle issues. In January i replaced the IAC and installed the jeep cables headlight relay kit and new headlights. This month i was having intermittent starting issues again so i replaced the alternator. I also put in a new PS pump and Tstat. She has been running great for about 2 weeks. Yesterday after work i went to start her and she was stone cold dead. I figured i had left the key on and drained the battery. opened the hood, checked the battery and she was fine, gave it another crank and she started and ran no problems. This morning, same thing. stone cold dead. i pooped the hood, touched the battery cables, but they were both tight, turned they key and she started, but now ran really low idle, I had to keep my foot on the peddle for a minute. I could release the pedal and she stay idling but really low rpms. I watched the RPM gauge and the idle was fluctuating like a bad IAC. Once she got up to temp i drove her to work, but at every light the idle was still low and rough.
Video of rpm idle

what do check now?

 

[Anak]

I don't know to what extent the Neutral Safety Switch (NSS) could be related to the running issues, but it could certainly be related to the no start issues. Varmint #1 ran into this with his '92 when the weather turned cold. Disassembly and cleaning of the NSS resolved the issue. Given your change of climate it might be worth checking out that component.

ETA: IIRC we used a low temp grease when we reassembled his NSS.

 

[Joshua13]

I don't know to what extent the Neutral Safety Switch (NSS) could be related to the running issues, but it could certainly be related to the no start issues. Varmint #1 ran into this with his '92 when the weather turned cold. Disassembly and cleaning of the NSS resolved the issue. Given your change of climate it might be worth checking out that component.

ETA: IIRC we used a low temp grease when we reassembled his NSS.

Oh, i did try starting it in neutral to see if that was the issue. it didnt work either. but thanks!

 

[75SV1]

I've had the issue with the NSS, or range selector for the 98+. Sometimes it would start in Neutral, and other times not. Same with Park. Sometimes, I could push the handle forward to back and it would start. You can use a jumper wire. I forget which terminals to jump. I have cleaned a couple of NSS(Range Selector). Hardess part is removing them from the trans.

 

[Unclewolverine]

Corrosion on your battery cables. Take them off and clean the battery terminals and inside of the clamps really good with sand paper.