Is the any way to test headlamp motors off the car?

 

hook it up to any 12v source. It'll spin if it's good...

 

All right motor spins but headlamp does not move.

 

Then the bushings in the gear are no good. They're easy to change out. I recently changed mine. Hawks sells a kit to rebuild this portion of the motor.
Hawks Third Gen Parts-82-02 Camaro and Firebird Parts - Firebird 87-92 Headlight Repair Kit
it costs $25.50. It includes 6 bushings, 2 side cover gaskets, 1 motor housing gasket, 2 motor housing screws, and a tube of white lithium grease.

When I did mine I just bought the bushings off ebay for $10, reused the old gaskets, and I already had white lithium grease. Always use plenty of this grease when reassembling these motors.

 

Just a heads up, The Headlight repair kit that Hawks sells is the one Top Down Solutions makes,
look at the photo and you'll even see the TDS logo.
I ordered directly from TDS, paid $5.50 less, and got in a day and a half.
and now my motors work again.

 

And as an additional data point, Lon (the guy who runs TDS) consistently gets excellent marks for customer service...