Switching 380/560 Switches

[Strife]

The power window switches take the most use of all the switches in the 107 SL, and they switch a lot of current. The later 380/560SL switches are older technology, with a frosted plastic disk built into the switch paddle passing light through a very thin (polycarbonate?) overlay. The light was probably originally a filament bulb, but the ones I have were yellowy-white LED's, and not very bright.

The overlays seem to wear out more quickly than the electromechanical parts of the switch, particularly the left one (no surprise there). The "black" of the polycarbonate comes off and allows light to come through, eventually looking ugly and making the legend hard to read. But what is surprising is that it's the left one that seems to be out of production. The left and right are interchangeable, but you wind up with two RH legends, and these switches are not cheap at the dealer and you aren't going to find a good LH switch used.

There are aftermarket switches (one-handed) , but beware that some are not lit at all, and some I've seen are pad-printed - the legend may wear off very quickly.

I got this idea from a guy selling stuff on eBay, to use better switches from a 201, namely, a 126 820 62 10 and -63 10 (left and right), which were apparently for the rear windows. These have much bigger legends, and are sort of "double-shot" where opaque plastic actually forms the legends in the black tops, which will last basically forever. So, I bought a few used (they aren't expensive). As I suspected, you can take the paddle tops off of those switches and put them on the 107's switches by prying them out, carefully, bending the sides of the body outwards and releasing the center pins from the holes in the switch body. I cay "carefully" because (easy to lose) parts could go flying, (like contacts and ball bearings).

Unfortunately, the 380SL's internal switch lighting, which on my switches consisted of the LED and a 1/8 watt resistor, were located under the original switch top's window legend, and not the center of the switch, leaving half of the switch dark. So, I replaced it with a ground-down T 1/34 "ultra-bright" white LED (leaving the resistor in circuit) and centered the LED. The act of grinding the LED also "frosted" it, making the light more diffuse. This is not for the squeamish and took some tricky soldering in tight quarters. I was very pleased with the results, although the 126 switch bodies have additional light shielding so that no unwanted light leaks out of the top and bottom of the switch. I might have prevented this in the 107 switch body by repositioning the LED a little higher, but you really have be picky to worry about this problem.

Another possibility would be to use the 201's switches "as-is". Unfortunately, there is an internal connection missing from this switch that the 107 (at least earlier models) need. It is possible to work around this by taking that pin (pin 7) and connecting it to pin 3. There was no contact in the female socket body in the 380's wiring harness for this, but these can be bought from the dealer. From there, you can splice the wire to the wire connecting to pin 3. Note that this modification would not prevent the use of the earlier switches should you decide to go back to original (these pins are correct for my car, and if you intend to do this, you need to look at the wiring diagram for your model year).

It would also be possible to replace the bulb inside the 126 switch with a high-brightness LED.

Contacts

The "lack of springiness" in these switches can be caused by the bronze contacts bending, and they can be carefully re-formed (a polite way to say, "re-bent") to the shape of a known good switch. Note that electrical problems (i.e., windows not going up or down) are generally also caused by this. Each contact has a spot-welded(?) button of probably silverplated metal. If one is worn and not contacting, the entire contact can be replaced from a spare switch - the contacts and rocker ball bearings were interchangeable between the 107 and 126 820 62 10/63 10 type switches. A little grease on the ball bearing areas during reassembly is a very good idea.

If you are junkyard-picking, these switches might be worth looking at if you are not concerned with originality on your 107. Even if you aren't going to use them, the contacts are interchangeable with the 107's contacts, so you could repair your switches with these. Lit with LED's or the original filaments, their appearance is superior. My antenna, defroster, and dome lamp switches look even dimmer now (I think they are dirty internally), and I will probably wind up putting LED's in those too.

[JimFreeh]

Great info, thanks!

Jim

[ctaylor738]

Nice wrench!