-Written by Steve Phillips for HotVWs Magazine -
I’m just going to talk about the common ones and not go back to the early 50’s. I guess first things first; the heater cables pull on the levers on the heater boxes which in turn put heat into the cab of the car. In a bug, when the heater is working properly you will notice that you can get third degree burns on your left foot and will still be frozen from the waist up. In a bus well you're trying to heat a barn with a candle. Kidding aside, if you take the time to make sure your heater system is working and is sealed up the heaters in these old VWs don’t work half bad.
Let's look at the heater cable(s) that the earlier vws have. If you have a knob that you twist like a water faucet, those are what I’m talking about. It’s a simple system, but a little tricky. Let's work on getting the old one out. Go under the car back by the motor and find where they come out of the horns (area that holds the motor and trans in), it will be right around where the axle boots are. Most of the time the end is broken off. If that’s the case then just make sure the wire is straight as it can be so it will pull out easier. There is a cable (wire) on each side. If you look under there and you see bailing wire, well now is a good time to undo all that mess.
Now back to the cab of the car. I use a rag and a pair of channel lock pliers and break loose the silver colored collar just under the knob. Start to unthread that collar. This will release a slide that rides in a tube. Once you have that collar undone you can just pull on the knob and the slide will come out. When you have it about two inches out, grab your pocket screwdriver the snap on man gave you for spending 10K dollars with him and push on the small pin that’s at the end of the slide. It is not a press fit at all so don’t lose this pin. Once the pin is out you can take the slide and pin and set it on a towel on the floor. What you should be looking at now is the loop in the wire. Pull on the loop and the cables (wires) should come out. That’s it you got them out. That’s the easy part. Putting this all back in is the tricky part. Grab your new cable. Sometimes these cables come pre bent, sometimes they do not. For the sake of this article lets say they aren’t. Have a friend help you here. What you want to do is take the two ends and hold them like the picture. Do not hold them even. Believe it or not one side has to be longer than the other. With your buddy holding the ends, run your hands up the wires and put a bend in the cable. Now they are ready to install. Take your flashlight and look down the hole the slide came out of. In the bottom of the hole you will see two small holes. Those are the holes the wires will be going through. Take both ends of the cable and start one down each hole. The long side goes in the hole on the passenger side. Ok feed the wires evenly into the holes. I try and smear some white grease on the wire as I go. Once the loop is close to the end of the tube it’s time to put the slide back on. This is the tricky part. Unscrew the knob while holding onto the slide, so that the slide is just about to fall off the screw part. Look closely at the slide and it has a cut or slot on one side. That slot has to ride in a little tab that sticks out of the tube. If it doesn’t the slide will spin. If it spins it just twists up the wires and the cables won't work. So with your finger find that little tab that’s inside the tube. Once you know that then line up the slide so the slot and tab will go together and put the slide over the looped end. Push the pin back in. Grease up the slide and push it gently down the hole. As you do make sure that little tab got into the slot. Now screw the knob down a little so you can start the collar back on. Thread the collar down. Now turn the knob counterclockwise until it bottoms out. That should be the off position. That’s it for the front. Time to climb back under the car and hook the cables to the heater boxes. If you crawl under and you see one cable is too long and the other is too short, guess what, you put them down the wrong holes. Take it back apart and switch holes. Before you tighten the barrel bolt on the wire, pull on it to take out any slack. Tighten the barrel bolt. Last thing here is to turn the knob to full on and then get back under the car and with your fingers push the lever on the heater box forward. Does it move? If yes then I readjust my barrel bolt so the lever is all the way open when I have the knob all the way to open. We need all the heat we can get here, especially if this is an early bus.
Bugs, Ghias, Type 3s, and Things have levers. This is semi similar to the earlier version. The cable or wire has a dog leg on one end and two wires coming off that dog leg. “But Steve I have two levers, won't there be a cable for each lever?” Nope you will have two cables or wires for each lever. Yes I know it's hard to believe but trust me this is the case. The lever towards the passenger seat is to turn the heat on. The lever towards the driver's seat is to open flaps under the rear seat. Bottom line: leave that lever down until your front window is defrosted. In other words you may never ever have to pull up on that lever. Go under the car back by the motor and find where cables come out of the horns (area that holds the motor and trans in), it will be right around where the axle boots are. Most of the time the end is broken off. If that’s the case then just make sure the wire is straight as it can be so it will pull out easier to pull out. There is a cable (wire) on each side. If you look under there and you see bailing wire, well now is a good time to undo all that mess. Now back to the cab of the car. To get to the cables you will have to take the E Brake boot off or damn near off. If it's easy, take the passenger seat out. Next, grab a 13mm wrench and start to take off the nylock nut that holds the lever on. Pay attention here. There is a lock style tab and some nylon washers. Not a bad idea to get your phone out and take a picture so you know how it stacks back up when you go to put it back together. Now take the lever and lean it towards the passenger side so it comes off the stud it pivots on. Then move the lever forward and pull at the same time. You should be able feed the cables with the dog leg end out of the tunnel area. Once you get the cables out grab your new cables. As before, one end is longer than the other. If you take a look with your flashlight you will see two tubes that the cables came out of. One is stacked on top of the other. Put the longer side cable in the bottom hole. Feed the cables in greasing them along the way in. Then get your lever back on the dog leg and fish the lever back into the tunnel and then back on to the stud it pivots on. Stack up your nylon washer and keep, then the nut. Tighten the nut barely snug. We want the lever to work easy but not so easy it falls down. Now push the lever down. Time to climb back under the car and hook the cables to the heater boxes. If you crawl under and you see one cable is too long and the other is too short, guess what, you put them down the wrong holes. Take it back apart and switch holes. Now tighten the barrel bolt. Last thing here is to pull up on the lever to full on and then get back under the car and with your fingers push the lever on the heater box forward. Does it move? If yes then I readjust my barrel bolt so the lever is all the way open when I have the knob all the way to open.
For Bay window buses this is a lot harder than on the other cars. One cable does one side unlike the others where there are two cables hooked together. First thing to do is find your sharpie marker. Now look under the dash where your heater and fresh air levers are. You are going to see cables hooked to a lever that has a lot of holes in it. Take your marker and mark what hole the cable came out of. Trust me, just do it. Now there is a spring clip that holds the end of the cable to the lever. Undo that spring. Now on early bay window buses up to 1971 you had a lever for each side. On the later buses you had one lever that did both sides and the two cables hooked together at the lever. So pay attention how this all went together as you take it apart. Get the cables out of the lever(s). Follow the cable down and you are going to see a bracket that the cable housing mount to. There is a spring clip that holds the cable housing to this bracket. This clip is a pain in the ass. The minute you undo it, it goes flying off and you spend the rest of the day trying to find it. Beware of that when you take it off. As soon as you undo the hook end of it, it will fall. On early bay windows there are two heater cables. On the later bays you have the two heater cables and a defroster cable. All held on by that one fricken flying clip. Remove the clip to get the housings free. Now under the bus at the rear. Find your heater boxes and start looking up around the area that the hose goes forward to the body for the heat to travel forward. You will have a barrel bolt there. That is if it's hooked up. If it's broken then straighten out the wire like I said before. If you see the famous bailing wire take it off. If the ends of the cable are still there you will see a plastic guide tube that will have to be popped out of its bracket and taken off the cable in order to get the end of the cable to go through the metal tube. Once you have all that mess taken off on both sides move up to the front of the bus but still underneath. Find where the heater cables go through the front clip and have your buddy help guide them down and out of the front clip area. I know I know this is a pain. Now you have them free under the front of the bus. Start pulling them out. One side at a time paying attention to the metal tube they came out of. I do one side at a time. Get the old one out and feed the new one in. Use white grease on the housing to help it slide into the tube. Push them all the way back towards the motor. When you think you got it go back to where they hook up and get your guide sleeve back on and push back into its bracket. Don’t hook it back to the heater box yet. Do the same thing to the other side. Now feed both cables back up though the front clip. Once you have that now get them back into the housing bracket and install the clip. Lot easier said than done. After you're done fighting that clip, put your cables back into the lever(s) the way they came out. Install your spring clip back on and move the levers up and down. If everything is working well then get back under the bus and hook the cables back to your heater boxes with your barrel bolts. Again same thing here. Put your levers in the off position and hook up your boxes at the rear. Then turn the levers on and see if you're opening the controls at the heater box all the
way. If you are, you're good. If not play with the barrel bolt until you do.
That’s it. As you can see buses are way harder to do then any of the other cars. One last note: I did not mention heater cable boots. These are nice to have as they keep crap out of the metal tubes. They are a pain to put on but in the long run of things worth the effort. I use lots of oil when trying to push the boots over the cables.