i have a 1984 porsche 944 will turn over but will not start i am not getting power to the fuel pump dose it ground through the ecm? i test the relay with a battery i ground pins 85 and 85b and relay works but when i plug the relay in i get no power to the fuel pump but i have power on the 85b pin so dose the 85b pin ground through the ecm if so could i have a bad ecm?
Have you checked continuity through the contacts of the closed relay? Because the relay solenoid is working does not mean the contacts aren’t fried.
If the relay is numbered 30-85-86-87a-87 the power flow to the pump is from pin 30 to 87. Default current flow is from 30 to 87a. Pins 85 and 86 control the closing. If 85 and 86 get power and ground from either direction the relay will close and connect battery voltage from pin 30 to 87.