4th Generation F-bodies have the same problem. Its due to the
protection circuit in the motor. Its a very very thin metal strip.
When a the motor overloads, such as hitting the stops and the button
not released, the metal strip expands. Thus, poping the circuit.
After cool down, circuit is closed. Over time, the metal looses it
abiliy to return to the closed position.
Things to do to fix the problem:
1: Buy a new motor and regulator, install it yourself. On
installation, CLEAN the regulator tracks, lube both the tracks and
gears. Just the motor can be replaced, available at any parts store.
You need to do more work to remove and attached the new motor to the
2: On the cheap, clean the tracks and lube both tracks and gears.
The tracks get gummy over time. Cleaning reduces that friction, don't
forget the rollers as they must be free to wobble. When you get the
regulator out, you'll see the rollars has a ball/socket attachment.
Google around for other tips.