I have a 2001 XJ and the battery went dead on me the other day (not sure why yet and this was unusual as the battery has never caused me any problems before). So I charge the battery overnight and put it back in this morning and everything fine, she starts up, I take it out for a spin and everything is good. I have left it all day and went to see if it had lost any charge in that time so that I could start troubleshooting it (which it hasn't). I put the key in the ignition and I have the driver door open because I'm not going anywhere and the horn sounds one constant noise not like an alarm. I close the door and the horn stops. I start up the Jeep no problems and I open the door again and the horn goes off again. It has never done this before and the battery has run down before when the starter motor stuck but I didn't get any issues with the horn.

I can't see anything in the manual about having the horn as an alarm and there is no after market security on the car so I'm at a loss to explain why the horn should be sounding. Anyone else had anything like this. I have the RKE but have never played around with this and it is on silent where the horn doesn't sound on lock.

 

Have you checked the switch on the back of the door lock cylinder? I'm guessing this and your battery are coincidental, and not related. OR, try manually unlock the door, close it, open it, and manually lock it. Or you can lock doors with power lock switch, close door, and then unlock and lock the door with your key.

 

Thanks for the suggestion. Went outside to take a look and the horn is NOT sounding when I open the door now!! it is never a dull day owning a Jeep!!

 

Do you have an overhead console or do you have a mini dome lamp?

In either case, the RKE module is in the overhead console/dome lamp.

As you know, the RKE has a feature to chirp the horn when you lock the Jeep using the fob. And...as you know, when the door is opened the dome light comes on.

Do you think there may be something afoot here?

You can drop the mini dome or console and examine the RKE/dome light wiring and see if there's anything amiss.

For the heck of it, try disabiling the RKE horn chirp and see what happens.

REMOTE KEYLESS ENTRY RECEIVER
PROGRAMMING

The optional Remote Keyless Entry (RKE) system for this vehicle has a customer programmable horn chirp feature. The horn chirp is requested by the RKE receiver through a hard-wired circuit to the horn relay, whenever a valid Lock message is received from a programmed RKE radio transmitter.

The purpose of the horn chirp is to provide the vehicle operator with an audible verification that the Lock request has been received by the RKE receiver.

However, for any number of reasons, some customers may prefer that this feature be disabled. This RKE system allows them that option.
To program the Remote Keyless Entry (RKE) receiver so that the horn chirp feature is disabled, proceed as follows:

(1) While within the reception range of the RKE receiver, press and hold the Lock button of a programmed RKE transmitter depressed for five to ten seconds.

(2) While holding the RKE transmitter Lock button depressed, press and release the RKE transmitter Unlock button.

(3) The RKE horn chirp feature is now disabled. Repeating the preceding steps will again enable the RKE horn chirp feature.

 

got a feeling that there might be something here with the console as I have just noticed that rain is getting in there from a leaking windshield. I am now thinking that the water may have caused a short. It is now dry and everything working as usual. I am waiting for a guy to come and reseal the windshield. A common problem in Jeeps I am told.

 

Where did that feeling come from pray tell....

 

the feeling came from a big drop of water landing on my hand as I was driving. Devine intervention? lol

 

OMG! Thank you for posting this! I looked my 98 over a few times for a cut wire or something that disabled the horn from activating with the alarm and lock/unlock functions to no avail.

 

I've had leaking windshields in both of my 2000 XJs. I can sympothize

1st one: I was slow to figure out the first. When it rained there would always be a little water on the floor, but I figured it was from my shoes. It took driving without shoes before I noticed. My symptoms were dash going blank (same error code when the data cable is unplugged). Also, it would run fine, but once it was shut off it wouldn't start back up. On a drive through steady heavy rain I ended up duct taping a plastic bag to the windshield after stopping to take a leak. It took about 30 min for it to dry enough to start back up.

2nd one: After I bought the jeep I took it to a car wash on a dry day and sprayed water around all the door and window seals. This one was leaking right in the middle of the top of the front windshield.

The 1st one was totaled before it ever got fixed. I pumped the second one full of rtv sealant and glued the rubber down. It doesn't leak, but I'm interested as to what the body shop sees when they replace it. New paint job should be finished within a week. I'm interested to see what my floor pan looks like, as I have no idea how much it leaked over the 10 years I didn't own it.