Sticking Sun Roof

["Powell, David" <David_Powell@CBSI.com>]

89 Audi 100
77K

The sun roof opens fine but when while closing, it bogs down, then stops.
It usually stops when it's about 3/4 of the way closed.  When this happens I
can't move it for a few moments.  I'm guessing I've overloaded a circuit
breaker when I stressed the motor.  I cleaned off all the rails I could
find.  Then I regreased them with white lithium.  This didn't help at all.
Any Ideas on how I can resolve this?

TIA,

David Powell
89 Audi 100