Late W124 models have the option of an armrest-mounted cellphone; the wiring is in place whether the cellphone was installed or not. With the help of GSXR (Thanks, Dave!) I found the cable under the seat and rerouted it to use with my garage door opener. Here’s how I did it. You’ll probably think of other uses so please suggest them.

The cable from the cellphone comes out of the armrest, passes through the driver’s seat and dives into the carpet, never to be seen again. It turns out that there’s a plug and socket in the cable hidden under the carpet. If you pull them up you can plug in your own device.









Please note that the connectors are RJ-45 (8 pins) network connectors. Standard 2-, 4-, or 6-pin telephone cables WILL NOT work. I used a female-to-female adapter and a network cable from my junk box. The cable was pulled under the carpet and up into the console.



The only switch with SPST momentary action that I could find in my collection was a rear window washer switch from a T-sedan (“station wagon”). Actually, it’s DPST but I ignored one set of contacts. The switch was installed in one of the positions in the “limo wood” console panel, available from Mercedes as an option for all 124s (124 683 38 37).



Only four wires are used so I removed the unneeded contacts from the socket. Two wires connect to the network cable for the garage door opener and two wires power the illumination of the switch.



A short stub of network cable was added to the opener in parallel with the existing switch. The opener can be removed from the car by unplugging the network cable from the armrest. This allows the opener to be used outside of the car and also makes changing the battery easier.



The opener now lives in the armrest where it’s out of the way yet easily accessible if needed. It has no problem from that location opening the garage door. I padded the opener with a spare pair of gloves so it won’t rattle.



Obviously you don’t have to use the same switch or the same switch location as I did. Wherever you put the switch, make sure it’s in a location where it can’t be accidentally pressed. You don’t want the cat opening the garage door in the middle of the night.

There have to be other uses – 8 wires is a lot, you could install an MP3 player, for example. Use your imagination!

Jeremy

EDIT: To remove a source of confusion, I changed the second sentence, which formerly read in part, " . . . I found the cable under the seat and rerouted it to use as a garage door opener." The sentence now reads "with my garage door opener."

__________________

"Buster" in the '95

Our all-Diesel family
1996 E300D (W210) . .338,000 miles Wife's car
2005 E320 CDI . . 113,000 miles My car
Santa Rosa population 176,762 (2022)
Total. . . . . . . . . . . . 627,762
"Oh lord won't you buy me a Mercedes Benz."
-- Janis Joplin, October 1, 1970