66gtk wrote
I haven't dove into diagnostics yet, but my heater/AC fan switch clicks into all the places but only works on full blast fan or off. I'm not sure where to start with figuring out what to do.
You really should start a new thread on this issue. It doesn't have anything to do with vacuum, although the switch is on the same piece of plastic as the HVAC vacuum switch.
Having said that, the EVTM has a section on the fan switch. See pages 147 and later here:
http://www.garysgaragemahal.com/ac-heater.html
Gary, AKA "Gary fellow":
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Dad's: '81 F150 Ranger XLT 4x4: Down for restomod: Full-roller "stroked 351M" w/Trick Flow heads & intake, EEC-V SEFI/E4OD/3.50 gears w/Kevlar clutches
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Big Blue: 1985 F250HD 4x4: 460/ZF5/3.55's, D60 w/Ox locker & 10.25 Sterling/Trutrac, Blue Top & Borgeson, & EEC-V MAF/SEFI