I just replaced the heater control levers and cables in my ‘86 runner. Everything is working smoothly except for the vent selection (top left). The cable and lever slide smoothly, but the actual selection mechanism (next to the gas pedal) is very stiff and doesn’t move unless I get down onto the floorboard and move it manually. Any suggestions?

 

When you move it manually, is it difficult, stiff, whatever? If it is, have you tried a short squirt of something like WD-40? Is the lever hard to move when the cable is clamped into the holders at the selection device, but not attached to the vent selector near the gas pedal? In other words, it's all set and clamped as though it were hooked up, but the center "wire" of the cable's bottom end isn't hooked to anything?
Sometimes, if the cable isn't routed exactly where the old came out, it can get sort of crimped, and very difficult to move.

Good fortune, and let us know how things go!
Pat☺

 

The mechanism next to the gas pedal is stiff, I’ve used some PB’laster to try and clean it up, then WD-40 to lubricate it some. Unattached, the levers and cables slide very smoothly. I don’t really want to take the plastic apart to clean it since I’m terrified I’ll break it.

 

Well, it seems to me like you have two choices. Leave it as is, and wait and see what breaks, or take the plastic parts apart to clean them. Either way, chances are you'll end up replacing them.

Before you start taking things part, maybe consider getting new parts in advance. If you break something, you've got what you need on-hand. If nothing breaks, but you clean and lubricate it all, problem solved. Plus you have some spare parts on hand for the next time it jams up.

Just checking, but did you give a squirt to any of the lever's far sides, if they stick out the other side of the box? The passenger side of the box. Maybe it's the far side that's jammed up, and just needs some lube. Maybe where the flapper valves inside the box are, are getting jammed up in a layer of dust/dirt. Taking the box apart might let you scrape out the dust/dirt to free the valves up. Often, also, the rubber foam seals on the valves inside the box get old and stiff, no longer allowing free movement. You may need to get some weather seal at you local hardware store to replace it with.
From what I recall, taking that box apart isn't all that difficult. It may well be jammed up with dust, dirt, whatever. Just be careful taking things apart. The most likely parts to break are the clips that hold the outer part of the cables. Very worst case, you're going to wind up in your local junkyard stripping out the parts you need.
There are places that do that to crash totaled older model Toyotas like ours. They strip them down completely, and sell just about any part you can think of. Try YotaYard.com, or others similar. Have your VIN ready, they use it ensure you get the right part for YOUR truck. They do have on-line ordering capability, but I've found that, at least at YotaYard, they get busy, and loose track of emailed orders. You might need to get on the phone to "remind" them of what you want.

Good luck, and keep us up to date on how things are going for you.
Pat☺

 

This is something that I need to address with my 4runner. I can get it to switch over to heat but it takes a lot of force, like something is going to break inside there. For now it's on heat and I won't switch it off till spring, so I've got some time. It's better than when we got the truck and the bypass valve was stuck on and there was no floor matting or insulation. It made for a bit of a hot ride on a summer day.

 

Could be the cable not routed properly, and not free to move. Very easy to do, trust me. <AHEM>
The FSM has almost no information on routing the cable, so you'll need to figure the proper routing yourself. Main thing is to ensure the outer sheath of the cable is free to flex, not tied down, or restricted by pressing up against other parts.

Another possibility is the water control valve getting old and sicky. Remove the cable from it and see if it moves easily. If not, replace it. Not expensive at all, and easy to replace. Two hoses, a cable, two bolts holding it on. Simple, quick, painless.

Good luck, let us know what you find...
Pat☺

 

I need one of these cables. Where did you purchase yours from?