Hey there. I am new to this, so please bear with me, but I need some help. I have a 1984 380SL R107 which I believe has a 116.962 engine. I am having the evidently common and dreaded high idle problem. My engine is at about 1600RPM in park and neutral and is about 700RPM in drive and reverse. I have purchased a new idle control valve (0001411625), overload protection relay (201-540-08-45-HBT), and a rebuilt idle control unit (Programma 002-545-33-32X).

I am using some downloaded wiring diagrams and repair manuals—both Mercedes and Mitchell Repair Information Company.
The Mercedes troubleshooting ladder diagram:
1. Switch ignition on and off. The ICV does not switch
2. Switch off engine, detach ICV connector and see of battery voltage exists. I got 0.38VDC.
3. I removed the Idle Control Unit and tested for battery voltage at terminals 2-4 and got 12VC
4. If voltage in 3 above exists, then jumper contacts 1, 2, 4, and 5 (briefly). Does ICV switch? No (note that I blew the 10A fuse on the overload protection relay as I was evidently not quick enough).
5. Test cables from contacts 1 an 5 between the Idle Control Unit and he ICV and had good continuity at .001 Ohms.
6. Tested continuity on the green/yellow cable from fuel pump relay term 10 to Idle Control Unit term 3 and had good continuity at .001 Ohms. I also went back and checked for voltage between these same two terminals and got a solid 12VDC.

Going through the troubleshooting ladder from Mitchell Repair which is slightly different:
1. Engine was warmed up to operating temperature. The engine was stopped, the connector to the idle control valve (ICV) was disconnected and the ignition was turned on without starting the engine. VDC=1.63.
2. Per direction, jumped to step 4. Unplugged the ICV only slightly and measured voltage with the engine running. Voltage across the terminals was VDC=1.98 V.
3. Step 5 stated that if the voltage measured is 4-6VDC, disconnect the oil temperature sensor wire and ground terminal and that idle speed should increase (?) to 750RPM. Although I am not inside these parameters, I did do this and RPM=1600.
4.Step 6 is to disconnect the ICV and with the engine running, apply voltage to the ICV terminals. It state that if idle speed drops or engine stalls, replace the idle control unit. For this I used 3 and then 4 C cell batteries in series and then a 9V battery. At this point things were a little different in that the idle speed had increased to 2000RPM from the previous 1500RPM, but here is what I got.

a. 4.7VDC=1600RPM
b. 6.3VDC=1400RPM
c. 9VDC=4-500RPM

So I do not know whether or not the idle control unit that I just bought is faulty or not. Suggestions?
I would appreciate any help I can get on this--MikeT