1991 190e ignition help

I need to find out how to test if the ign module is recieving a td signal. I only have a haynes book for a 1988 190e, so hthe wiring is different. I have a td signal at the diagnostic plug of about 8 volts, but nothing at the fuel pump relay. I need to isolate if the problem is the ign mod or if I have a broken wire. I was also surprised to see the car run with the fuel pump relay jumped and the ign mod unplugged. I assume it was running on a pulse signal from the crank sensor. Where does the ign mod get the td from and if possible what color is the wiring in the ign mod connector. Thanks in advance for any help.