I have just recently replaced the heater cables in my '81 Vanagon, so I figured I'd write the procedure down before I forget it.
This procedure was written for an air-cooled Vanagon. I imagine the procedure is similar for an air-cooled Bus but I don't know for sure. This will be of no value to those with water-cooled Vanagons.
The heater cables on my Vanagon were in need of replacement. The ends where they connected to the flapper boxes at the rear of the van were in bad shape, so heat had to be turned off an on at the flapper boxes rather than using the lever on the dashboard. Since winter will be here soon, I replaced the cables to be done with it.
I got the cables from Kyle Wade at Volks-Motorsports. He had them for a good price, though it took some time to get one of them as it was on backorder. There are two separate cables for the Vanagon, both of which attach to the heat control lever on the dashboard. I don't know if the cables are different lengths but I do know that they have different ends, and you must have both a left and a right cable to do the job properly.
The first step in replacement is to remove the instrument cluster, so that means disconnecting the battery. Be sure to do this before you start.
To remove the instrument cluster, first pop the cover off. Then remove the plastic sheet that covers all the goodies in there. After you've done that, remove the various switches from the cluster. It's apparent how they come out, simply squeeze the tabs together and pull them out from behind the cluster. You will need to remove all of them except the headlight switch. I have found it easier to simply disconnect the wiring connector plug from the headlight switch rather than removing the whole thing.
Now you must remove the four screws that hold the instrument cluster to the dashboard. Trivial.
Now you have two more disconnections to make: unscrew the speedometer cable from the back of the speedometer, and then pull the big plastic plug from the connector on the rear of the clock. Now the instrument cluster pulls right off the dash. Set it somewhere where you won't step on it.
Now you can clearly see and reach the heater cables where they attach to the lever. To remove them you first need to remove the cables from the lever. You notice that one cable has an L-shaped attachment on the end while the other has a loop. You notice that the L goes through the lever and the loop hooks onto the L on the other side, and is secured with a circlip.
You have to remove the circlip, which can be coaxed off with a screwdriver. DON'T LOSE IT!!! After you remove the circlip, separate the cables and remove them from the lever.
Now you've got to go to the rear of the van and do some dissassembly. You need to free the cables from the flapper boxes, so however they are attached, figure out how to undo it. Mine were sort of free-floating so I have no idea what the original setup was. What the other Buses use won't work on the air-cooled Vanagon, though Kyle sent me 4 barrel clamps to use, which I will detail later.
Somewhere on the cable you will find a grey plastic doohickey. Remove it from the cable but don't damage it as you will need it later. If I recall correctly, that is about all you need to do to free the cables on that end. Now you will want to tie a string around one of the cables (I recommend using a ball of string and letting the ball unravel rather than cutting a length of string), making a knot before the large cylindrical end. Make sure it won't come off the cable halfway through the cable sheath.
You will notice that the new cables come with the cable already inside a sheath and then the whole deal goes inside another sheath to the rear of the van. You're going to be pulling the cable out of the plastic sheath through the dashboard.
So now that you've got your string set up, go to the front and start pulling that cable out. If I recall correctly, the left cable is the one with the L-shaped end while the right one has the loop. If you find it hanging up when you attempt to pull on it, go back and find out what it's hanging up on. You may need to coax the whole thing into the plastic sheath initially. Once you've got it pulling, just pull the whole thing out from inside the van. The cable should come through easily, bringing the string you tied to it at the end. Remove the string from the old cable, and tie it to the same place on the new cable.
Get a little grease (wheel bearing grease will do) and grease the black rubber sheath on the new cable, then stick it down into the plastic sheath, cylindrical end first (also the end with the string tied to it). Shove it through for a bit, then go to the back of the van and pull the string from there to help it along. Go back and forth doing this, while continuing to apply grease every now and then to the cable.
When you've got that one all the way through, go to the other side and do the same thing.
OK, so now you have the new cables both installed and ready to hook up. In the dash, put the L-shaped cable end through the lever and then hook the loop end of the other cable around it, and then put the circlip on. I know, easier said then done. Be patient, and don't kink the cables!! They will be ruined if you kink them.
Once you have that done, then you need to make your connections at the back. Depending on the hardware you have, this may be done differently. I'll leave you to figure out how best to do this as I'm not too impressed with my solution. I ran the cables through the holes on the flapper arms, and then used a barrel clamp on each cable to keep it from slipping through the hole in the arm. It works, but it's not elegant and I know it's not original. The picture that the Haynes and Bentley manuals show of the flapper box is not the type of flapper box I have on my van.
Now, before you try to move the cables with the lever, read this: Remember that grey plastic thing you took off? OK, if you remembered where it goes, put it back there. If not, then find the little metal thing that goes around the cable a little ways back from the cylindrical end by the flapper boxes. Snap the plastic thing around that metal doohickey, with the narrow end toward the front of the van, wide end toward the rear. This will keep the metal thing on the cable from hanging up on that cable bracket thing back there and kinking the cable. Trust me on this, as I kinked the right cable finding this out. I had to order a new cable.
Once you've done this, you can adjust the cables. Obviously, when the lever is on the "off" position, you want the flappers to be closed, and when the lever goes to "full on" you want the flappers fully open. So adjust your method of attachment to achieve these flapper positions.
Once you've done that, that's pretty much it. You need to put your instrument panel back together, so don't forget to hook everything back up, including the instrument panel power connection (big one behind the clock) and the speedometer cable. If you don't get the big connection in securely, it will make your instrument lights do weird things, so double check that if you get some weirdness.
Hook the battery back up and reset your clock and you're done. It's not too difficult a job, but it can be frustrating. Take your time and be sure not to kink the cables.
Sean Bartnik
September 23, 1997