stuck hvac selector

[joecat66]

recently I noticed my HVAC selector for defrost, feet and face is stuck to the right on face. I can move it 2/3rds of an inch or so to the left but it is hung up for sure and

forcing it feels like something will break. Any ideas where to begin before I tear into the dash. I was doing some under the hood detailing with a spray bottle and soapy water

along the firewall but that may just be a coincidence.

thanks
joe

 

[OSS]

The push-pull cable for HVAC stuff is solid steel sliding through an outer sheath. That steel cable can rust on the outer ends that are open to atmosphere and create a lot of friction on the end points as it’s forced through its sheath.

Remove the climate control face plate to get at the cables and spray some lube in them and try to get them sliding smoothly again.
If you force it too hard you can bend the cable — and then it won’t work at all.

 

[joecat66]

The push-pull cable for HVAC stuff is solid steel sliding through an outer sheath. That steel cable can rust on the outer ends that are open to atmosphere and create a lot of friction on the end points as it’s forced through its sheath.

Remove the climate control face plate to get at the cables and spray some lube in them and try to get them sliding smoothly again.
If you force it too hard you can bend the cable — and then it won’t work at all.

much like the old 10 speed..I'll take that off and start spritzing thanks!

 

[4runner2FJ60]

Good advice. One of my cables is bent, the one that does fresh air or inside....PO. Is there a fix for that?

 

[g-man]

pull the heater controls out of the dash and disconnect the offending cable. Then see if the offending heater control slide works without the cable connected. You know, process of elimination. If the slide is still sticking you know you need to lube the heater controls and get them moving again. As mentioned above make sure the cable moves in the sheathing. Then...

Also look under the dash and follow the cable to the arm it's connected to at the vent/ducts. Remove the cable and use your hand to make sure the arm can move the linkage and door. The slide that goes from hot to cold goes to the heater valve on the firewall in the engine compartment. This can have an arm that gets stuck or corroded in place and may need some spray lube and gentle working of the mechanism to get it moving again.

 

[CruiserTrash]

much like the old 10 speed..I'll take that off and start spritzing thanks!

It’s exactly like a bicycle brake or shifter cable + housing. Same with the choke cable. I had a stuck hot/cold slider, so I removed the HVAC bezel and faceplate, detached the cable from the slider and from the coolant valve on the engine bay side of the firewall, and pulled the cable completely out. I sprayed a full can of brake cleaner through the housing, wiped down the cable really well, then sprayed in the housing and on the cable with Teflon lubricant. Reinstalled and works perfectly now.

30-40 year old truck. Every little thing is gummy, dirty, sticky. And every little thing needs a good cleaning.

 

[joecat66]

update
I had the hvac faceplate off , and was able to get some lube on the cable. The selector arm pivots off a hinge and the cable connects to it. Things up top did not seem rusted and there was a little movement. In hindsight a shot right through the middle of the selector slot would hit the cable end and eliminate removal. I knew then the problem was where the cable terminates. That location is to the right of your foot if it was on the accelerator. Kinda behind the ducting top left side of the trans hump. There is a more complex hinge set up there. I was able to get a good shot of wd40 all over it and w/my right hand up top and the left aiding the linkage below I was able to move the lever completely side to side. I can now move it with just the lever but it requires more force than necessary so it is not quite right but working. The lower assembly has plastic parts and will require removal of the duct work to trouble shoot further...perhaps there is a clip that holds the cable on that end that has let go as i still feel some binding

 

[georgebj60]

perhaps there is a clip that holds the cable on that end that has let go as i still feel some binding

This is your most likely scenario. There are clips that hold the cable in position, so that any force you're putting on the level is not wasted in bulging the cable, but is moving the flaps. They are usually metal, about 1/2" wide that the cable snaps into. All those plastic bits that you were hitting with WD40 are not likely to get bound up. The tolerances aren't that tight on those parts. BUT, if there was something blocking the flaps from moving into position, this could make it bind up.

There are a few threads on refurbishing heater boxes, and after 30+ years, it's overdue. Long overdue. Debris in the boxes is very likely.

 

[joecat66]

final chapter
After reassembling the top controls and writing my update we took the truck out to the recently opened for the season dirt roads in the Pachaug Forrest near my home for some hiking. The air diverter control is back to gliding like new...the WD must have need a little more time to work itself in. I can also feel the little clicks between the 3 main settings. At least I now know where all the controls end surprisingly all can be lubed without getting into the dash