My son's away visiting his girlfriend across the country, leaving his car here. While it's not in service I decided to try a few things:
Wednesday, August 23, 2023 <>I removed and took apart the trunk lock. It was very corroded and sludgy inside, it looked like there was vaseline packed in there. It was the corrosion preventing the key from inserting, some of the wafers simply wouldn't slide. The secret to disassembly is the internal snap-ring at the back of the lock cylinder, which holds it all together. After that it was careful wafer freeing and a minor filing to get the corrosion off of the wafers. I used a lot of brake cleaner to sluice out all the dirt, grease, and etc. Then correct (graphite) lubrication, and reassembly. This all took a lot more time than it should have, mostly because of unfamiliarity. The trunk lock works much as in older cars, except there is not a mechanical 2-state tab that lets the trunk be opened manually when the car is unlocked. On this car that is done electro-pneumatically, via the locking system computer. Summary: The trunk can be locked, mechanically, so that it can only be opened with the key, by turning it hard to the right and removing it. (Valet function, you remove the mechanical key from the fob and keep it, and give the valet the fob. They can't get into either the trunk or the glovebox if those have been locked with the key. Also useful if you want to secure the trunk contents against a potential thief bashing in a window and using the interior trunk release.) The trunk can be unlocked, mechanically, by turning the key hard to the left, reversing the above condition. (The key is spring-loaded and cannot be left in that position, it'll move back to the center position afterwards.) The key can be removed in the center position, which is 'normal', or the right position, which is locked. The trunk can be opened, mechanically, by turning the key hard to the left and then pushing in. This will work even if the car is completely dead. With the lock in the center position, 'normal', the trunk can be opened electro-pneumatically, with one of: Interior switch; Key fob; Pushing in the trunk lock, if the car is unlocked. All of these (4.X) require the car to be 'alive', with no electrical or pneumatic faults in the locking system. This car, at acquisition, could only do the very last two of these. At the moment it's only 4.1 that it can't do. I then removed the interior trunk release switch, by pulling up on the panel. Now the reason for the extreme expense of this (also apparently NLA) switch became apparent: it is all the switches! Windows, mirror, trunk release, child switch, airbag indicator, all in one large assembly. P/N 210 821 39 51. Good news, and bad news. Good news: yes, the C330 trunk switch mechanicals I scored at the junkyard are the same, right down to the numbers molded into them. Bad news: it's the housing, containing the hinge pins, that is broken, not the moving parts. The housing is very large and specific to this particular switch assembly. So I got out the Shoe Goo, and started trying to fix the breaks. I'm trying to splint the breaks using sheet metal. If there's room for the necessary splints. Being a hinge it's a high-stress point, simple glue will not be sufficient. Thursday, August 24, 2023 <>After some filing the splint works, and the pivoting piece can still move. Now for the other side, which is entirely missing the plastic double-ended hinge pin. (Broken out of the housing, and missing.) After some thought I got a piece of 12ga copper wire and started hammering it down in diameter on one end until it fit into the holes in the pivoting pieces. I then cut off a bit of about the right length, and Shoe-Gooed it into place centered in the housing. One plastic piece will pivot on the inside nub, and one on the outside nub. Friday, August 25, 2023 <>After some careful filing to make the new copper hinge nubs the right length I snapped the two moving plastic pieces of the switch into place. Mechanically it seems OK again, though I shall have to caution Daniel to be very careful with it, as I'm sure it's not very strong. I installed it in the car, and it works perfectly. Now all the trunk functions are correct. The S.O.S. switch was broken, and falling down out of the headliner. I cut up a large paperclip and used its pieces to secure the flip-down red cover, and to secure the switch body into the headliner. Very ghetto, but definitely better than before. I used Goo Gone to clean off the door handles and such that were grimy. A little better looking inside. Three of the jack point covers were in the ashtray, and looking at them I see why. The plastic protrusions that hold them in place are broken off. Looking at the fourth I can see that it's probably the same, as clear tape is being used to hold it in place on the car. I got out the clear packing tape and did the same to the others. It looks better with the holes plugged, at least. My intent is to pick him up at the airport using his car, and to pop the trunk from the inside when he walks up. Surprise! -- Jim _______________________________________ http://www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
