Heater control cables: which, where?

Guys,

I have a 1973 CJ5 with original heater controls. They're the ones with three push-pull knobs mounted through a plastic box that bolts under the dash. There are three lengths. One slightly shorter than the other, the third is much shorter than the others. Where does the shortest cable connect to? I connected the longest to the outside air plenum flapper, the second longest one to the hot-cold flapper, and the shortest to the flapper that directs air either to your feet or to the defroster duct. Having trouble with this shortest one. Even though it's the closest to the control panel I'm wondering if it should have a longer cable so it can do a racetrack loop instead of sharp bends to the flapper lever. I already broke the knob messing around with it so I'll have to super-glue it and I sorely don't want to break it again.

Thanks,
Chilly

 

My 72 has a steel bracket that mounts below the dash. The left cable is the shortest (approx. 20 inches) and it connects to the mode valve, the center cable connects to the air inlet valve and you turn the knob to control the blower speed and the right knob is for the temperature valve. I was lucky a few years ago and found an old mail Jeep in a salvage yard that had the same controls as my CJ5. All of the 73 and later intermediate CJs that I have seen have the plastic box controls like you described.

 

From left to right, it's AIR DEF TEMP. The parts book gives three different part numbers for the three cables, so I presume they are all of different length. The 73-75 has the plastic bracket which seems to always be broken. Unlike the '72, there is a toggle switch for the fan speed.

I don't have my head under the dash of my Jeep right now, so I can't tell you the routing. You've identified the three places they attach to on the heater. The shortest cable goes to the defroster flap; connection visible under the dash. The connection on the body of the heater is the heat control.

The cable sheaths are plastic, looks like nylon or delrin, and should slide easily. I don't thnk the cable length is the problem. I think the main problem is that the plastic used for the heater control housing (bracket on the dash) gets brittle over time, and can't stand up to the force needed to move the heater flaps. You might make sure the flaps move easily, and that the cables are ok; otherwise, I think your only option is to somehow reinforce the back of the (weak) plastic bracket.

 

i sure wish these cables were available. I'd love to replace my DEF cable.

 

IIRC somebody out there is selling the cables aftermarket... search.

 

I had some link to a vintage cj5 place, but the website says out of stock 100% of the time.

 

Mmm. That's probably the same place I'm thinking of.

You should be able to find a used one. An intact housing is hard to find, but the cables seem to survive ok.

 

Well, if the short cable goes to the defroster flapper then it must be a problem with the cable. It has some rust on the steel part of the cable. And the flapper is a little sticky. I've been thinking of how I might mount a simple bell crank to link the push-pull cable to the flapper instead of forcing it into such sharp bends. Or maybe I'll dip the cable in boiling water and try to form it?

 

Quadra-tec has all three sizes for a 77-86 .don't know if they would work on yours. i bought all three to use on my 69' with aftermarket heater.

mike s.

 

76+ are different. They might work but the oddball would look out of place and the lengths are most probably wrong but easy enough to adjust. If I go with anything other than the correct parts I'd just go with some heavy duty push-pull cables from NAPA, which are of higher quality than any Jeep OEM control cables. But I'd like to keep the original look since my Jeep is fairly unmolested and in pretty good condition.

 

I don't think the hot water ploy is such a good idea. If the cable is corroded already, that will make it worse. Heat gun would be better, or infrared lamp.

What exactly is the problem - the cable doesn't move in the sheath, or the sheath won't bend to the proper path? Or something else?

 

The problem is the path from the heater control panel to the defroster flapper is short and requires the cable to bend at a couple of very tight radii. Tight enough that the push-pull cable doesn't face straight in the heater control box and I fear I'll break the last remaining unbroken box known to Jeepdom. And when I DID get it connected the sharp bends, and probably some corrosion inside the sheath, bound up the works. That's when I pulled too hard and broke off the knob. Now, I could cut off the loop and pull the cable out of the sheath so I could clean off the rust and lube it up. But then the cable would be shorter. I could probably heat the cable with torch and wrap around a 1/4" bolt to recreate the loop but I'm still getting shorter.