This afternoon I replaced the wiper motor with a $32 NOS one from ebay. It solved the only high speed and no parking problem.
It's not an easy job, but it could have been worse. It took me over 2 hours, working a bit slowly like I do. I found that I needed to remove the dash panel with the wiper & headlight switch to get better access to the top and left mounting bolts, which the Chilton manual doesn't mention. Setting the parking brake also opens access to the left mounting bolt that is otherwise blocked.
You have to transfer the 3 mounting bushings and the rubber cone seal that is supposed to keep water from getting inside the cab. And of course the arm that connects the motor to the linkage.
You have to remove the 2 screws that hold the fuse panel to this bracket and then remove the 2 bolts that hold this bracket in. Getting the bracket out and back in isn't too easy due to wire bunches and other brackets being in the way. The upper bolt had to be taped to a deep socket and a LONG extension used to put it back.
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The white thing visible under the vent is the top portion of old wiper motor.
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Lined up the arrows on the arm and the new motor.
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But then I pulled the arm back off and used a 3/4" socket and a dead blow hammer to install the arm AFTER the motor as mounted so I didn't have to fish it through the smallish hole.
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If you don't have one of these screwdrivers, GET ONE! It makes removing and installing the 4 screws down into the cowl a breeze. No dropping them in and having to fish them back out.
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Now it's working perfectly.
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