wiper motor turning, but clutch mechanism lets go

88 turbo coupe. Took another set of mechanism arms out of parts car (found cracked bushing on original). Still does the same thing.

Wiper arms move OK, swapped motor from other car too.

Any suggestions?

Matt, I pulled this off the web many years ago. I don't think to original link even exists any more.I'm not sure what problem your having so I'll offer this up. Hope it helps.

this comes from the aerobird faq

7.0 Common repairs

7.1 Windshield Wipers won't return to "rest" position. This is a common
problem on all Aero birds that is easily fixed in less than 30 minutes. I
have successfully repaired two cars with this same problem.

1. Open the Hood, and prop it up.

2. Turn the ignition key down to the accessory position, and turn on the
wipers. turn the ignition key back to OFF when the wipers are at the end of
their sweep, farthest from rest.

3. Locate the wiper motor on the upper right on the firewall (to the right
of the master brake cylinder).

4. Remove the wiring harness plug from the wiper motor. This may prove
difficult if the plug has been on the motor for some time.

5. Using a socket, remove the three screws that hold the entire wiper motor
assembly from the firewall. Note: do not remove just the motor cover, remove
the entire assembly.

6. Pull the assembly away from the firewall, and carefully remove the
locking clip from the wiper motor arm. You may need to use a screwdriver.

7. Slide the wiper linkage arm off of the wiper motor arm, and remove the
entire assembly from the car.

8. Directly under the wiper motor arm, there is a rectangular plate that
slides horizontally between two guide plates. These plates, over time, will
bend downward and let the plate spin freely. This prevents the wipers from
lowering properly, although they may work fine in normal operation.
Lubricate the inside of the guide rails with grease. Line up the rectangular
plate between the guide rails, with the notch on the top of the rectangular
plate towards the passenger side of the motor assembly.

9. Using a flathead screwdriver, gently pry the rails back until they fit
snugly with the rectangular plate.

10. To test the motor assembly, attach the wiring harness, and place the
motor on a cloth to insulate it from any grounds in the engine compartment.
Turn the key to accessory, and run the wipers though all of their speeds,
making sure that the wiper motor arm stops in the same place every time they
wipers are turned off.

11. Disconnect the wiring harness, and beginning with step 7, work backwards
to reinstall the wiper motor assembly. Test the wipers once the motor is
installed in the car. If they still do not work properly, it is a problem
with wiring, or internally with the motor and it should be replaced.

Unfortunately, the mechanism seems to be tight enough to make the "clutch" break free. The blades barely move from the spot they start from, going up maybe 1"

Crazy how rare this problem is.