Bill:
I waited a day hoping someone with more knowledge would reply but they are too slow so here goes...this is from memory (not too reliable) and is by a real amateur (me) so forgive errors here...
This is about replacing the heater levers on a 1971 280 SL with AC and Becker Europa radio…
The job is not technically difficult (even I was able to do it!) but the fear of the unknown can freeze your hands…since the parts are not super critical and are not moving at high speed, you can take your time and think things through while looking at the problem…
The Service Bulletin posted by Admin is very useful even for a 280 since the differences are minor. There is some difference in the dash opening but in a 280, access is through the radio hole anyway…
As to a source for the levers, they are often on ebay as a set and are also available from parts dealers, need four at about $35 each. I bought mine from Tom Hanson of Caliber Motors, an MB dealer. Cost was about twice as much but I wanted to believe I had the best and since they will last many years (I hope), I spent the extra $. I believe mine are the later style, softer lever tab for safety. Original hard tabs are no longer available and are probably not “correct” for a late 280 SL.
Need two red, one blue, one smoke (gray). Can change the bulbs at the same time if you don’t want to go back in later. I didn’t change the bulbs (I may be sorry.)
With an AC, access from below is not possible, so I removed the radio and speaker to get access from the top and front, and the glove box for access from the side.
Remove one cable from the battery to prevent problems from a loose wire touching a ground etc.
Glove Box: open the box, remove the screws on top and bottom. Start to bring the box forward with the lid open. Watch the springs on the left side, they are a bear to work with. They do not have to be removed. The lid does not need to be removed. As the box comes out, unscrew the wires for the glovebox light on a terminal board behind the box. I put the two screws back into the board so as not to lose them.
Clock: now reach behind the clock and remove the single nut holding the bracket to the center post. Watch how the bracket goes on. Push the clock into the car, reach behind and remove the single connector. It can go on only one way. Repair the clock or send it away if it needs it.
Radio: Europa face chrome surround is held by friction fit. Just pull both sides of the chrome gently and it will come off. Then remove the knobs. Usually held by a tiny screw on the side, loosen the screw with a very small jeweler screwdriver. Then pry off the bass adjuster ring on the left knob shaft. The gray striped face plate should just come off. Two white metal upright “holders” fasten the radio to the dash. Remove these to allow the radio to be pulled out. Note how they are positioned. (I made lots of drawings and still got confused). Bag and label all parts.
As the radio comes out, reach in and disconnect the antenna wire, the power wire, the speaker wire. Now remove the two screws holding the speaker wood grill. Remove any baffle material on top of the speaker. Take out the screws holding the speaker. Might need a stubby phillips here. Remove the speaker and wire.
Now you should have lever area access front, top, and side. If the levers are working at all, test the function of each cable. If they are stuck, you need to work on the cables and the heater valves else the levers will break again. I did not have to do this. The two reds are heater valve cables, the blue is for the outside fresh air in front of the windshield. There is a two inch round rubber cover top of the firewall, drivers side, for access to this cable. Suggest you open this cover, check the cable movement and put some lithium grease on the moving parts.
Now to the levers (at last). Prepare to suffer cuts and scrapes on wrist and arm, keep calm and smile
)
A couple of hidden nuts can be felt on the rear of the lever area face plate or can be seen through the windshield. The Service Bulletin shows a special tool used at an up angle. I assume you do not have this tool. I used a socket (maybe 8 or 10mm?) on a short shaft with a universal swivel attachment.
The small (1 inch) center piece with the diagram printed on it will come off allowing the two larger pieces to be removed sideways.
Each cable is held to the lever unit by a screw and a clip. I think that at least the top right cable must be detached before the entire until can be taken out for access to the other cables. This cable has no play so it has to come off. The top right cable can be removed while the unit is still in the dash. Not sure about this, so pull the unit a little as you look to see what’s holding things in then remove the obstacle. I believe that two of the levers have to be moved to the outside position for access. The Service Bulletin mentions this.
Eventually, the entire unit will come out through the dash opening. Now you have easy and painless access to work at a bench to remove the old levers (and bulbs?) and install new, match the correct lever colors. This is the easy part of the job. Suggest some lithium grease in the groove of each lever track.
And as they say, installation is reverse of removal.
Took about 6 hours with an assistant (but can be done by one patient person.)
Hope I haven’t left out important stuff and that others will chime in with corrections.
I then went on to repair the speedo, install new tach and speedo cables, remove and clean up the wood trim but you didn’t ask about that (thank goodness).
Richard M