Where is the starter motor relay located on a 1990 ford F150?
Find the positive battery terminal. Follow the thick cable from that terminal and it will lead to the starter solenoid.
In the 1999 Trooper the relay is sbove the inside fuses. It is above the fuse door, so that the whole panel by bottom of the driver door must be pulled. Don't know if that helps for 1990. Note: My fuse, relay and motor are good, but no power to motor. added 1/22/2008 The blower motor resistor is located on the housing located on the firewall. This housing is were the blower motor is.