The fan starting when the car cold starts: if your car is like my 87, 260E, then your coolant temp sensor may be bad. The sensor (a switch in reality) is telling the rest of the circuit that the engine is very hot. On my 260E, the sensor is the 2nd last from the windshield side, on the engine. It has 3 terminals, single terminal is for compressor cut-off relay (Klima) and the other two terminals are for the aux. fan, and if you disconnect the two terminals, the fan should stop. And if the fan is on because of this temp sensor, it should be running on high speed. I had a similar problem after a prolonged period of not driving the car, there is somthing about lack of coolant circulation and these sensors going bad.

The radio problem also sounds familiar, one time I changed the battery and the radio died, never came back again, had to replace the front controller part.

About the starter lockout switch, in my car the power to the fuel pump relay, socket terminal 9, is available after the starter lockout switch (thats what the diagram seem to suggest), so if you get close to 12V on this terminal of the fuel relay socket, the lockout switch is fine and if you dont get 12V, the switch is bad. You can even tell from the buzz of the fuel pump when ignition is turned to run, a buzz means starter lockout switch is o.k.

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Saumil S. Patel