Discussions related to electrical and fuel system, gasoline, etc.
You are right the knob when turned is threaded so it will move up and down which will push or pull the cable connected to the motor as well as open the vacuum flow thru the switch. By sucking on one tube (until I was about ready to pass out) and turning the knob I could tell there was a reduction in vacuum flow thus it does work to some extent only in a vacuum flow. Perhaps I can just by pass the vacuum tubes around the switch and use it to move the slide valve on the motor only. Max Merritt or Kanter will not service the switch or have replacements, I will check with Flackmaster. It's interesting that the 1937 Packard Operating Manuals, Shop Manual, or the Kuehl Restoration book really don't say anything about the wiper operation! Thanks All!
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