First off, welcome to HAN. :cheers:

We don't get a lot of first-gen (86-89) owners these days. :happysad:
Sadly, I don't have a factory manual for your model year, so I can't tell you where the sunroof relay is. h:

That said, I think the problem might lie in the mechanical components.

When you re-installed the motor, are you confident that the motor shaft engaged the toothed drive wheel assembly?

1. On the 94-01 models, there's a adjustment nut at the base of the cable assembly that pre-loads the drivewheel clutch. If that clutch preload adjustment is too loose, the motor will spin, but the drivewheel won't grip the cables to draw the sunroof open. Based on your description of the components in your model year, I would expect a similar system in your car.

Do you hear the motor turn when you hit the sunroof switch?
Or does it sound like it's straining under load? :dunno:

2: I know it sounds like blind conjecture, but somehow I suspect it's the motor or the cable assembly that are part of the problem. Solenoids don't lose their ability to transmit power over time; they usually fail outright -- like a fuse.

If the tracks are clean and lubed... and the clutch is properly adjusted... and the motor is receiving power, then the motor armature or commutator brushes may be dead. With a seventeen-year-old car, it's a distinct possibilty.

My 2¥. h:

Once again, welcome to the board.