If you decide that the power window motor is bad (which is very common), be sure to inspect the faulty motor. If you take it apart, you may find that there are 3 disintegrated nylon plugs that have deteriorated between the plastic gear and drive gear. If they have gone bad, you can replace them with new plugs found at NAPA (about $8. I think they are only listed for fords, but they aren't rocket science. They can be trimmed to fit) instead of spending $50 on a new motor. These plugs are found on power window motors and headlight motors (older pontiacs).

There are a lot of malfunctions that could cause this problem. One possible cause is a failing ignition control module. The ICM sometimes runs for a while until it gets hot, then stops functioning. After it is allowed to cool, it resumes function until, you guess it; it gets hot again. The ICM is located on the distributor on that engine (somewhat isolated from engine heat) and is a solid state electronic part. A failing ICM will (usually) not leave a DTC in the ECM. I'm not saying this is the cause of your problem. I'm saying that it may be the cause.

There are 4 screws at the base of the steering column that typically come loose. Disassembly of the steering column is necessary. 1st - Remove the steering wheel by loosening the nut under the horn button; then use a steering wheel puller to pull the steering wheel off of the splined hub. 2nd - Remove the steering wheel lock plate by using the lock plate puller tool to press the lock plate down; then remove the retaining ring. 3rd - Carefully remove the turn signal cancel cam; turn signal switch; key switch and plastic collar. 4th - Remove the steering column pivot pins. There is a special too for this job. 5th - You should now have access to the 4 loose bolts. They use an external torx head. Remove the bolts, one by one; apply threadlocker to the threads, then reinstall bolts. This is the basic run down (from memory) of the job, there may be some additional (simple) steps. A good tech can knock one out in under 45 mins, however, if this is your first one; take your time and allow several hours for this...