Hi:
It sounds like there is a vacuum problem. You will need to remove the switch assembly, find where the vac hoses plug into it, and check if any of them are getting vacuum from the engine. If not, you will need to follow the vac hose back to the engine checking for breaks or damage.
If it is getting vacuum, the switch assembly most likely needs replaced.
Let me know what you find before making any final decisions.
Joe
Jun 6, 2020 at 12:59 PM
(Merged)