1996 Jeep Cherokee Electrical Problem

Hey everyone, I have a 1996 Jeep Cherokee Classic 4.0. It has started blowing Fuse #9 that per the manual is a 10 AMP for Radio/Clock & Memory, Courtesy Lights, Glove Box, Cargo Dome Lights and Tell Tales. It recently started after hooking up a uhaul trailer to it. To use the trailer, we started with the bulbs with the pig tails, and then replaced that with a Napa wiring kit, we blew fuses with the pig tails right away, and never did leave the lot that day. We have had sucess with the wiring harness but even without trailers attached I am now blowing this 10 Amp fuse. It woked for a few days after the install of the wiring harness. I have since removed the wiring harness, verfied all the tail light bulbs are the originals, and I am still blowing this fuse. It blows when I hit the power door lock switch. Not everytime, sometimes I can blow a couple in a few minutes, other times it can be days before a fuse burns. Sometimes it blows while running, sometimes with no key in the ignition. It has tripped from the drivers and passenger door lock switch with or without the radio or air conditioning.

Will a 12.5 AMP (is there such a thing) or a 15 AMP work?

Other suggestions? I'd hate to bring this to a mechanic, because it will probably work fine for them.

Suggestions? Help!

John

I've seen other threads where someone recommended replacing a 10 amp fuse with a higher one but that is not the solution to the problem and may well lead to a more serious problem down the way.

The wiring diagram that I have does not show the first circuits you mention with the power door lock circuit so there must be some coincidince there.

Can you varify what circuits quit working when this fuse blows? Make a list of the functions that don't work anymore so you know what you are dealing with.

find a wiring diagram for this machine if you can.

Sometimes the local library will have car repair books that you can use or photo copy a few pages from.

This is a start for you and if you have other questions thats what we are here for.

JD

That is part of the problem. I have the Chilton Manual and the owners manual. The owners manual had an addendum with updated fuse assignments. The Chilton manual does not match my fuse panel anywhere, and the wiring diagram in Chilton for my model shows fuse 9 for Door lock switches (which I have checked out and not replaced since I have blown the fuse from both driver and passenger switches) and relays . Per Chilton it is also for remote keyless entry, and the radio, and per the owner manual addendum what I listed before..

When the fuse blows, I lose power door locks, Interior lights and radio. I can't verify the keyless entry since my transmitter does not work.

Can someone else with the 1996 Jeep Classic check what size fuse they have in postion 9 under the dash. My couterpart, thinks we may have used an available smaller size fuse on day 1 of the trailer fiasco, but of course he is not certain.

Thanks,

John

The sevice manual I have shows that #9 fuse is a 10 amp.

It protects the:

radio/clock & memory
courtesy lights
glove box lite
cargo lite
dome lites
vanity lites
power mirror switch
telltales

It also supplies power to the keyless entry module and the door lock switches.

There is nothing in the wiring diagrams to connect it to the tail lite curcuit unless you have some how connected something to the cargo lamp instead.

It seems to me that the tail lite/trailer thing might be a coincidence with this #9 fuse and not related at all. (Just a thought)

One of the first things I would note is does the fuse blow when locking or unlocking or both? There might be high mechanical resistance in the linkage at one of the doors or one of the lock motors is shorting out.

If it only blows only when locking, switch the 2 door lock relays in the relay bank to see if the fuse blows in the opposit function - it might be a bad relay.

Check the wires where they pass from the body to the door. you might have to remove the door panels to check the wires inside.

You describe this as an irregular occurance so that makes it even harder to find unless you can identify a common factor that is present every time the fuse blows.

See what you find and let us know

JD

JD,

I'll get cracking on your suggestions tonight/later this week. I had not thought about the relays or resistnace could be a problem. I believe it is blowing fuses when both locking and unlocking.

I'll let you know what I find out.

JD thanks for the tips, I think you called it right... the next day, 1 unlock (pushing the switch to unlcok) and the fuse blew, I drove home, replaced the fuse..... did three or 4 locks and it did not blow. I then did 1 unlock and it blew again. So I swapped the lock and unlock relays. I have not had a problem since. It has been 4 days. Can I explain it, no, but I'll take it.

Thanks again,
John

Glad it worked out for you.

JD