How do the HVAC controls / switches work? (1 Viewer)

[vankho]

It's hot AF in the southwest, so like many others, the AC is top of mind. I probably need a recharge and convert to R134a and all that, but in the meanwhile, the HVAC switches don't work well. The temperature control switch just springs back to one location. The air circulation location switch is super stiff. Fan speed and defrost switches seem okay. I'm trying to research, before tearing through the console and dash. How does the mechanism tie into the whole AC and Cooling systems? Is there some type of cabling system in place?

 

[CruiserTrash]

The hot/cold control is a cable that actuates a coolant valve on the firewall of my 60. I pulled the whole cable out, took it out of the housing, cleaned and lubed it. Much better now. The vent selector is also mechanical and is pretty stiff in mine - it moves a big baffle, so that tiny thing is having to move a lot of weight. Cleaning helps stuff, but being mechanical it is what it is to an extent.

 

[vankho]

The hot/cold control is a cable that actuates a coolant valve on the firewall of my 60. I pulled the whole cable out, took it out of the housing, cleaned and lubed it. Much better now. The vent selector is also mechanical and is pretty stiff in mine - it moves a big baffle, so that tiny thing is having to move a lot of weight. Cleaning helps stuff, but being mechanical it is what it is to an extent.

Super helpful! Thanks @CruiserTrash! I'll take a look at the firewall and see how things hook up there. Is removing the cable pretty straightforward as I assume that it is... removing the heater control panel and disconnecting some lines?

 

[CruiserTrash]

Super helpful! Thanks @CruiserTrash! I'll take a look at the firewall and see how things hook up there. Is removing the cable pretty straightforward as I assume that it is... removing the heater control panel and disconnecting some lines?

Removing the temp control cable/housing is straightforward but not easy. It’s a lot of reaching way deep into the guts of the dash. If you have big forearms I suggest you employ some children to help. Getting the cable out of the housing can be a pain - for me it was. I sprayed the cable and the inside of the housing with WD40, then put the cable back in and moved it around to loosen debris, then took it out to let it dry. I blew in some canned lock lubricant or Teflon or some kind of thing then reassembled. Not perfect but better.

 

[OSS]

My sliders stopped working properly after too much camping on the beach. Salt air corroded everything. The steel cable starts rusting inside their sleeves near the opening and don't slide as easily. The cable will then bend and then the game is over. I was able to get mine sliding back & forth easily again just by spraying lube at the cable sleeve interface and working the cable in & out repeatedly until the lube walked it's way down a bit - and then they were as good as new. Didn't have to remove anything .

 

[2mbb]

Besides the cable check that the water valve mounted on the firewall moves freely from stop to stop. You can disconnect the cable, close the valve and leave it for the summer.

 

[vankho]

Thank you again everyone for pointing me in the right direction. I was able to find additional documentation and take look inside and it's all starting to make sense to me. Looking forward to tackling this project now. Incase anyone else is going down this road here's some additional resources that helped me wrap my head around the cabling and the overall mechanism. I have to say, the water valve I have seems stuck? It doesn't nudge at all in any direction. Upload a picture of it for reference. A replacement might be in order?

 

[mbx118]

Yeah the hot/cold slider moves a cable for both the water valve on the engine compartment firewall (55907A) and a blend door in the airbox that covers the heater core (55909A). Little bit harder to set up since it controls two things at once.

 

[vankho]

Had a go at sorting out the cables this weekend and everything seems missing or out of place. If anyone can provide insight or have pictures it would be greatly appreciated.

Thanks @mbx118 for pointing out that the hot/cold slider controls two cables as that was the first inconsistency I noticed. On mine, 55909A was attached to the top slider for vent switch and tied to the frame via zip tie.

I’ve run the lines to the correct switches now I think. However, the two cables attached to the temperature switch aren’t clamped down like the other ones and just move around when I try to use the switch. The diagram doesn’t mention any clamps. Are they supposed to be clamped down? Can someone confirm if the two open spots on the frame are for clamps?