DIY 1st gear start, 80-85 S-Class

[pmckechnie]

I was messing around with my 84 500SEL and found that it has a thing called "Moving off 1st gear" This is the system that makes it start off in 1st gear when the shifter is moved to 3 or 2. It didn't work on my car and I traced the problem to the NSS. I got to thinking, what if I just put a switch where I could get to it. Well, I used an old rear interior light switch and hooked the wire that normally goes to the NSS to one terminal and Ignition power to the other. Put the switch in the position used by the radio fader and I now have 1st GEAR START that can be disabled by turning off the added switch. Cost, nothing.
After checking I found that all 80-85 126 and 107 cars have this system. This is information I got from Alldata so it may not be correct, but I know that 84 and 85 500SELs have it. I'm sure it could be used on other models. It is a very simple system. There is a special relay or control unit that only has 4 wires. It only needs a speed signal from the speedometer, a ground, 12 volts that is switched on and off by the switch I added, and a wire down to the kickdown switch under the gas peddle.
It works great, can be disabled and very low cost if you can get the parts at the local PAP.

Paul