'98 cherokee sport won't start after replacing heater core
 

Good evening all. This is my first post and I'm sorry if this has been covered in another post, but I have searched and only found posts similar to my problem but not exactly what I have going on. My son just bought a 98 cherokee sport 4.0l and we replaced the heater core. Now it won't start, won't turn over, click, nothing. When I turned to key to the "on" position the dash lights came on and when I turned it to "start" the dash lights and radio would go out and the brake light would come on. I tried it in park and neutral, even jiggled the shifter in both positions, and still nothing. We took the dash apart thinking we missed a connection somewhere, but everything was connected. All the posts I have seen talked about the NSS or starter. My son bought it last week and we put about 50 miles on it and was started at least a dozen time before hearter core replacement, with no problem. I find it hard to believe the NSS or starter would just go without out any signs, but I'm not a mechanic. Any help would be greatly appreciated. Thanks.

Was the battery disconnected before and during heater core service? Did you re-check for clean and tight battery post connections, jump it or try another battery?

Do you have fuel? Do you have spark? Did you make certain the PCM is plugged in? Did you perhaps spill coolant on an electrical connection? They're can be sensitive and it happens.

I don't think it's a NSS issue.


Recheck all connectors under the dash, and at the steering column.


C201 is often overlooked for being secure (bolt tightened), check it.


Attachment 313118

Thanks for the input everyone. My son and I tore the dash out 3 times, checked connections under hood and found nothing. 😡 We figured the last thing to try was the NSS. I followed a post on here that explained how to take it apart and clean it. It took about an hour and a half and the thing starts right up. I didn't think the switch would just go like that but it did. So if anyone in NW CT needs a hearter core or NSS just let my son or I know we are experts now. 😀

Yeah, they can go that fast. Glad you got it fixed and learned something in the process.

4WD4EVER. AGREE 100%. Starter does go bad with no warning. Starter an easy fix!

Take your son. A set of wrenches. A bag of brill pads. (No soap) Nad follow cruiser54's tips on clean your grounds. It's good bonding time with your kid. And keeps them running. Cheap. Only cost elbow grease.
I also checked/cleaned the connections to the main fuse box in the engine bay. It corrodes.
Grounds. Grounds. Grounds.
They are weak in this vehicle. And keep it running!

I’ve seen this too many times in the last few days with drivers using their running lights as headlights which causes the lights on the back of the car to be dark thus making it hard for other drivers to see them.
Please use your actual headlights at night!nox vidmate mobdro

I am confused. How do the lights factor in with a no-start?

Subaru's!
 

All Subaru's I swear! They need to make an idiot light on the dash for it ha ha 😜

thank you for calling this out! love it!!!

i know it’s an old thread and an old reply, but I saw this while looking for useful information, and the comment you called out was not at all useful. thank you for saying something so that i didn’t have to. lol

Speaking of useful information. What are you searching for?