Hey guys, sorry if this turns out to already be answered however I did try and research this problem and found nothing to help.

This winter my 2000 Jeep Cherokee Sport started to get electrical problems up the yin-yang.

All at once the following is occurring:

The horn stays on (HORRRRNNNNNNNNN!) [pulled fuse for now]

The rear defroster either stays on always, or doesn't work at all (when it doesn't work holding the button makes it stay on, but the fuse box on the passenger side starts making noise, relay?)

Interior lights stay on [pulled fuse for now, but no dashboard guages now ;[ )

Now to add to this, when I push and hold the defroster switch the dome lights turn off and the horn stops. Whats up with that?

Sounds to me that everything is related to the defroster. Later today I'm going to change the defroster relay and any fuses relative to the system. And will provide an update on how that works out.

 

Your XJ is dying...

Sounds like the famous 'electrical agenda' of the XJ has plans.
With electrical issues there are a few basic things ususally handy, regardless what the specific issue is.
You could get down to business with wiring diagrams and all, which I can not give any advice on. But checking all your fuses and relays is a start, make sure your battery is good and charged and connections and grounds are tight and clean. Do a good inspection of the wiring and poke your head under the dash, look for melted/burned wires or connectors. Multiple things are involved together, by what you discribe

The interior lights staying on....Make sure you turned the light '****' all the way back

For the rest, I can't help you much, since electrics is not my thing. But since you're 'bumped' others will have a chance to add.

 

Hey just an update in case this helps anyone in the future.

I failed to mention a constant clicking behind the steering wheel.

Yesterday I cleaned up the main ground wire at the battery and the block and replaced the turn signal relay.

Things have been going back to normal. Horn stays off, electrical seems fine.

 

Glad you figured it out. That was going to be my first suggestion. A bad battery ground can cause all kinds of weird things to happen.