I did a search on here and can’t find the answer to this issue. I rebuilt my trico wiper motor on my 29 coach. All went well it went together easier than I thought. I  tested it and it works pretty well but it won’t park. I figured there was some dirt in a passage that was causing the issue. I disassemble the top and checked the paddle thinking I may have installed I backwards and the little park washer might be on the wrong side. It was in correctly.  I tested it again and it still wouldn't park. 

I tried the mystery oil trick (putting some mystery oil in to help clear the passages and now it barely works at all. It moves back and forth but now it won’t reverse without manual assistance. My vacuum gauge reads 15 at a high idle which I think is adequate to make the motor work. 

There is an on off switch on the motor but no way to reach it in the cab. The dash has a knob that controls vacuum to the motor. Is this the right motor for this car? It’s odd there is a switch outside the car that controls the wiper motor and a vacuum dial inside that controls the vacuum feed to it. If it is the right motor what position should the switch on the motor be in to allow it ot work and park. 

Thanks

Rich