1989 300SEL Engine/Motor #103981 12 070224.
When I try to start the car it will run for a couple of seconds and the stops. When this first started the tachometer would jump up and then settled back at zero. Now it no longer gets off zero. I have done the following tests:
Continuity from CIS-E pin #25 to Fuel pump relay pin #10 to A/C Klima relay #2 to X11 pin 1 to Crank Position sensor #31 all checks out.
The fuel pumps are cutting out after a couple of seconds. Apparently no TD Signal.
If I jumper Fuel Relay Pins 7 & 8 the car will run.
Checking voltage while the car is running at X11 between pins #2 and #3 and get 6.1 AC volts.
Crankshaft position sensor from #7 to #31 has 871 Ohms.
Problem comes here..
Jumper Fuel Pump #7 and #8, Turn the ignition from Fuel Pump Relay pin #9 to #11 get Battery Voltage.
However from Fuel Pump #10 to #11 NOTHING.
Could a bad Tachometer be my problem?

I have another symptom/problem...My Fuse/Relay Box has a special label under Relays "C" and "D" designating them as "CC" and "DD".
There is no Relay "F" just a hole. And if I leave relay "I" in the power to my windshield wipers and radio doesn't go off when I turn the key off.
If I put it in and don't turn the key all is well, but as soon as I turn the key relay "I" locks in and stays energized. The only way to stop the radio and wipers power is to pull the relay. HELP PLEASE