Hello all, and thank you in advance for any help you might be able to lend. My wife has a 1999 Jeep Cherokee Sport with the 4.0 I-6 and yesterday it blew the fuse #18 in the under the hood fuse panel and it keeps blowing it. The first time, I replaced it and it lasted a few minutes. Now it blows it instantly as soon as you hit the key.

When you need help, I find it best to go to the experts and forums about your specific model of vehicle usually know the idiosyncrasies of the platform. What should I check first? Or is there something that is known to fail that would cause this issue?

As I said, thank you for any help you might be able to lend. It is very much appreciated.

 

18 is the driver window and locks, powers seats if you have them etc. So that likely indicates you have a short in the door. Might be a leak that has corroded a wire or you could have a pinched wire in the bundle of wires coming through the door. You need an upholstery tool to pop the interior panel off and take a look. Bought mine at autozone for 12 bucks.

 

It is the fuse panel under the hood, so fuse #18 is to the ignition rail coils and fuel injectors. All of the injectors test at 12ohms. I have not checked the ignition coils yet but I am not entirely for certain how to check coil rails like the '99 Jeep Cherokees have.

 

For anyone who might come across this thread in the future, I replaced the coil rail and all seems to be fine now. Nearly 200K on the odometer, even if it did not fix this issue it was still due. If it fails again here shortly I will post a reply, but this seems to have taken care of it.

 

Well I suppose that is encouraging since that was the fuse that kept blowing. Good luck!