The antenna won't go up or down & motor makes a horrible noise.

Just unplug the cable at the antenna (pull back the carpet) IIRC the fuse the disables powers a bunch of others things also

Pull the fuse in the fuse panel for the antenna.

should be a fuse in the (fusebox) just for the antenna. simply take the fuse out! make sure that fuse does not control anything else!!!

Find access to where the antenna motor is, and visually inspect/trace what kind of electrical connection there is going to it. It may be a simple unplugging of two connectors. I am suspecting that the antenna motor and the radio share the same fuse, as the power from the radio passes thru to the antenna motor when the radio gets turned on. So, can't just pull the fuse. But if there is a fuse JUST for the antenna, then pull it out.

The antenna is wired to go down when the key is turned off. The motor is probably stripped out. You need to replace the motor at the base of the antenna, or unplug the bad one to make it quit running with the key off

You need to pull the fuse for the antenna or just unplug it. It has a fairly ridgid plastic wire that pushes the antenna up and down. Works fine until the wire breaks then it rolls up (antenna down) but it never increases resistance because the antenna never comes down , it's like a fishing reel when the lure breaks off, so the motor thinks that the antenna is still coming down and it will run and run and run trying to do it's job. Your lucky it stuck up and not down. If you want your antenna to go up and down again you'll have to buy and install a new one.

Relay #27 in the box under the hood runs only the power antenna on a 1992. For the future here's the parts guide for everything in your jeep. Page 180 has a picture of what you want to pull.

http://jeepgarage.free.fr/OWN/1991-1993parts-catalog.pdf

disconnect the antenna motor.

you can cut power to it by disconnecting the plug where particulary is it located? on the vehicle i will be able to tell you how to gain access to it.

Look in the trun k on the ant side and pull back the the felt and you will see where it connects and disconnects. You have a broken antenna lead. At the bottom of all electronic antennas is a plastic lead that fits in the motor to wind the antenna up or down.The motor is still good you only need to replace the stem. Good luck.