xanderz

Update: Car is up and running. I bought multiple 30A fuses and put one in and after a jumpstart since my battery was dead, the car was running. I will be checking tomorrow for any wire issue.

Roler

You've blown a 30Amp fuse, and no cause identified yet.
So, without doing some diagnostics, you'd be driving around waiting for things to happen again.

It may seem intimidating to dive into electrics etc, but start with the simple stuff first. Look at and get your hands on cables, wires and connections, look for damage, loose connections, melted plastic, corrosion, etc. It's a good first step to get into this and we can take it from there.

Do you happen to have a digital multimeter?

318SixPack

Only time I had a very similar problem it was the wiring harnesses to the front O2 sensor. Wires touched exhaust manifold got crispy and shorted.. But mine blew 2 or 3 fuses in a row and I had it towed to a shop that found and fixed it.

xanderz

I just acquired a digital multimeter and want to get to the bottom of this problem I have because the fuse has blown a couple times now and I can't figure it out. Do you have any advice?

xanderz

I'm confused. Phillippe, Could you explain what you would do with the multimeter for me?

RockyMtn96XJ

It can be difficult to explain the usage of a multimeter to someone that is unfamiliar with one, especially trying to describe a very specific procedure. See if you can find some youtube videos on "how to check for continuity with a multimeter" , "use multimeter to check for broken wires in my car", "finding an open or short in car wiring", something like that. Then you can get caught up in the worm hole of learning that stuff. It really is simple, but hard to explain via a post on a forum...

Here are some other terms you can use in your searches:
find cause of blown relay in 1996 Cherokee (jeep, XJ, 4.0, etc)
cause of blown fuse in 96 cherokee
find cause of F20 blown
use multimeter to troubleshoot wiring and blown fuse in car
Auto shut down relay/fuse blown
Checking for open vs short in car wiring
Checking for ground because a fuse blew in my car

Or any combination that makes sense....

RockyMtn96XJ

Why is 96 the oddball year? What the odd part about it?

boxburn

I've heard many times that there are certain things on the 96's that aren't found elsewhere. I've seen a 96 with 97+ body but still the badges of a pre 97. The linked thread with the PDC at the start of this thread says it's not found on earlier or later years. I'm no expert on it so that's about all I've got.

Back on topic, the fuse blowing goes from the fuse, to the ASD Relay, from the relay and to the alternator, ingition coil and injectors. This will be long and may be difficult to follow.

• Ignition off
• Remove Fuse 20
• Set the multimeter to 20 DVC. You may see a symbol that looks like _ with --- directly below it.
• Place one probe on the battery negative and the other on one side of the fuse holder. One side should read +12V and the other 0V
• Now set the multimeter to continuity, it usually has an audio symbol like )))
• Keep one probe on the battery negative and place the other on the side of the fuse holder that read 0V. Placing it on the +12V may damage the meter while in continuity setting.
• You should see either 1 or OL which means there is no path to ground. If you see numbers or it bleeps at you, it means there is a path to ground which would indicate your short to ground.
• Next remove the ASD relay. There are 5 pins, 3 in a line then 2 below them. Refer to the PDC image you posted earlier
• Take one probe and put it on the 0V side of the fuse holder and the other on pin 16 of the relay slot. This should show continuity, if it doesn't, try pin 17.
• Which ever contact did not show continuity, probe that against the battery negative. You may see some continuity reading but it should be a high number. If you see a relatively low number, that's going to be the short to ground that you need to chase. You can try disconnecting the wires to the alternator (careful not to short out), coil pack and injectors one by one and see if the reading ever changes. Also getting someone to wiggle all of the wires in these areas while you check for continuity is a good idea as it may isolate it to a section of loom.

Good luck