Greetings,

I've been chasing the dreaded a/c blowing out the vent problem for a few years and think I finally traced the problem down to the PVH solenoid. The previous owner was not too smart (nor me). When I got the truck he said the 4WD worked and I trusted him....my bad. Anyway, it didn't work and the first problem I found was both vacuum lines to the PVH's were broke. When he was offroad he likely engaged the 4WD switch and the PVH solenoid opened up and sucked in some debris or water via the broken lines to the PVH's. That clogged it or damaged it. Fast forward.....I installed some manual hubs to get the 4WD system working. The PVH solenoid was replace by the previous owner however I believe he messed it up. Anyway......I replaced alot of the vacuum lines and end fittings over the years troubleshooting. Doing some more troubleshooting today I bypassed the PVH solenoid and low and behold the a/c system blew like it was supposed to. The question I have now.....because I converted to manual hubs, do I still need to replace the bad PVH solenoid or can I keep the vacuum lines bypassed and not replace the solenoid? Flipping the 4WD selector inside the cab seems to work as advertised. Thanks....

 

You don't need the PVH solenoid or vacuum lines, all can be removed

The PVH solenoid's vacuum source is the Vacuum reservoir which is also the source for the cab vents, which was why you had the problem
There will be a "T" on the vacuum line running from the reservoir to the cab firewall, that is for the PVH solenoid, cap it off or put in a splice, and remove the "T"

Vacuum diagram here: https://therangerstation.com/tech_li...-00_Ranger.gif

HVAC is the cab vent control

 

Ron, Thanks for the reply. I just wanted to make sure I did not need a functioning PVH solenoid electrically for the 4WD system or some other electrical system (ECM/PCM??). I have the vacuum lines tied into each other now. Thanks again for the reply.....John