Just unplug the power wire below the motor or the fuse in the fuse box..
Open up the truck.. Unplug power line but, don't unplug the antenna line. It's will be used for your remote. - email@example.com
Mounted to a relay thats screwd in to the plastic glovebox. just open it unscrew the screws and take it out and you will see the relay attatched to the glovebox.
First physical pull the antenna all the way up, clean the antenna very good with a degreaser, then lubricate it with a silicon spray. Open the trunk, unplug the power to the antenna, start your car with the radio turned on, stop the engine, plug the power source to antenna back in. Try it now, if you still have the same problem, either the relay is stuck and needs replacing or the antenna motor is shorted and needs to be replaced.
Check your RPO codes. If it has an U75 than it had a power antenna. If it has RPO code US6 it has a painted fixed antenna. There was only one style power antenna used from the factory.
unplug the electrical from the antenna. replace antenna.
If the antenna is in the up position, you have 2 options, replace the entire assembly, or unplug it. In the trunk under the antenna, you will find a set of 3 wires going into a relay. Unplug those, and the motor will turn off.
It isn't an easy job as you have to remove the inner finder panel.
the power antenna is located on right front. I jacked my car, and removed the right front wheel. Then there are some small screws which are keep the inner fender plastic. unscrew them. You can reach with your hand the power antenna. Unplug the power wire, and the antenna wire, and unscrew those small (8mm) screws which are holding the antenna in its bracket.
You can access the antenna and motor by pulling out the trunk carpet lining, then once you have a new one just unplug the old one and stick the new one in ;)
Try turning the radio off before turning the car off. If this doesn't work, check the assembly at the base of the antenna for a sensor switch for gunk and clean it off. Don't ask me where it is, because I don't have the schematics for the antenna assembly on a 1992 Cutlass Ciera handy at this moment. If this doesn't work, the easiest "fix" is to wait until the antenna goes all the way up, then clip the power lead to the antenna motor. Just make sure you don't clip the antenna lead. This will keep the antenna up all the time. Next cheapest route is to replace the whole antenna assembly, motor and all. I would recommend getting a cheap $5 standard antenna from a local auto parts store and do away with the "convenience" of the automatic retractable antenna.
Remove the wiring harness from the bottom of your 1987 Buick Regal power antenna. Remove the power antenna retaining nuts. The power antenna will come off. Reverse the process to install the new power antenna.