Tuesday, August 7, 2007 I didn't have much time this morning, but I managed to remove the ashtray, console cover, and ACC panel. Four of the five lamps behind the panel were burned out. The ashtray frame retention screw holes were stripped so I smeared some Shoe Goo into them, I'll redrill pilot holes when it dries. One of the screws was missing, I had to dig a replacement out of the junk box. The retaining pin for the console cover is broken off and missing, it was (at one time) stuck down at the rear with a wad of double-sided foam tape. I'll have to fabricate a new pin. The rubber shift bezel was starting to crack in the corners so I began gluing it using black weatherstrip cement. The console cover itself needs sanding and refinishing, the finish has started flaking off and the wood has gotten wet and swelled some. The wood cover for the ACC panel got its screw retaining blocks broken off somewhere along the line so I glued them back on.
As I remove panels and trim the car's starting to not look so good, and it's only going to get worse before it gets better! ...I opened up the ACC pushbutton array, and the solder joints are indeed bad inside. In the evening I did some poring over the car's schematic and augmented the diagnostic checklist to have some test information for the ACC system used in these cars. (We currently have five cars using this particular system, it's about time I made up a checklist for them.) Wednesday, August 8, 2007 I resoldered the ACC pushbutton array. The secret here is to use a very hot iron on the internal relay pins themselves, these are the ones that tend to oxidize, break loose, and make bad contact. The edge joints that attach the two side boards are also problematic, but they're easy to resolder with a regular iron. I sluiced the switches themselves with contact cleaner and cycled them many times. I then liberated a spare high-fan blower button from the junkbox and installed it in place of the missing button. I replaced the four burned-out 2721 bulbs with new ones. I then ran the appropriate diagnostic checklist in the car, and discovered that the blower system was not working. Nor did it work with the ACC panel installed, helping to validate the checklist. I also found that the foam hose to the cabin temperature sensor was indeed rotted, but that the sensor itself measured good. The AC compressor, as expected, also did not run. I then reinstalled the repaired ACC panel. Finally some positive cosmetic treatment! On the way to work it became apparent that the heater blower _was_ working properly, and that the checklist was faulty, as was my quick functional test. (I'd forgotten the effect of the cold engine lockout sensor.) However the vent control wasn't right, all vents operated all the time. Could be a vacuum supply problem. (Let's hope so!) Bad actuators are no fun to replace in this car. ...At lunch I stopped at McParts and bought some replacement 2721 lamps, and two clearance cans of "Torreador Red" touch-up paint, $3. The cap was a surprisingly close match, we'll see how it looks in real life. Thursday, August 9, 2007 I hooked up the vacuum pump to the feed under the hood and pulled out the ACC panel again. Using a test light to power the actuators (built-in current limiting) I found that the defrost actuator is the only one that is obviously leaking. I pulled the instrument cluster and unhooked the vacuum lines to the defrost actuator and capped them off. It looks like it might be possible to replace this actuator without removing the dash, I may try doing this sometime. (It won't be easy, regardless.) The center vent actuator (a nightmare to replace) actually seemed to be working properly once the defrost leak was stemmed, but when I looked down in the center vent I could see that something was wrong. I pulled off the rubber vent manifold and could then see that the ring on the flap that the actuator end snaps to had broken and the actuator was no longer connected. I cleaned the remains, fabricated a folded-over piece of thin sheet metal with appropriately-sized holes drilled in it, and glued this over the stub using Shoe Goo. I'll let that set up and then try reattaching the actuator. Even though the center vent control line is referenced to power and not ground, if you're doing the testing key-off (as I was) you can feed positive voltage to it to make it go: the unpowered car circuitry acts as a virtual ground. While I was there I figured out what was wrong with my blower test checklist item. (You have to jumper _two_ pins, not just one.) This time it passed! With all that to the stopping point I got out the rattle-can of touch-up paint and sprayed some onto a couple of the big missing chunks. This was a color test, and it didn't look too bad in the morning light (shade). It's a tiny bit redder than it ought to be, but I think it's going to work out well enough. I sprayed a bunch into the cap and used a small strip of sheet metal to dab it onto the rock chips and etc. I also dabbed some clear spray onto the scratch in the clear coat that some kind parking lot-mate gave me recently. It's lumped up, but less visible than it was. I'll block-sand it down flush later once it's dry. ...When I got home from work I popped the cluster out again and attached the now-dry center vent tab to its actuator using a short screw and a nut that I dabbed paint into the threads to serve as a lock. To improve visibility I removed the center vent eyeballs, that really eased the job. When I tested it the tab bound a bit, but a few licks with a file took off the high corner that was catching on the air horn. Works great! With the eyeballs out I was able to thoroughly clean the grime and dust off of them, I did the inside of the center vent air horn too. I then managed to get the defrost actuator speed nuts off (two of the three broke) and found that the actuator seems to have come unclipped from the flaps inside the ductwork! The original plan was to see if I could swap the actuator guts with a good used one that I have that has a twist-lock mount, and failing that I was going to temporarily lock the flap in the closed position, but there's no point in doing the former and no way to do the latter. There's nothing for it except to pull the dash and open up the heater box. That is not going to be fun, I'm not sure when I'll do that. Not soon. The rotted foam hose was very exposed at this point, I cut a length of foam pipe insulation and put it on. Then I reinstalled the center vent parts and buttoned up the car. We're going to be gone for a week so I enlisted some aid to put the hard top back on. It doesn't fit very well, either it or the car itself is deformed. Probably the top got dropped at some point, its 'chrome' trim is a bit dinged. It's manageable, just not as easy as the other three SL's I have experience with. Once it's locked down it's fine. -- Jim _______________________________________ http://www.okiebenz.com For new parts see official list sponsor: http://www.buymbparts.com/ For used parts email [EMAIL PROTECTED] To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
