The relay is just forward of the glow plug relay/controller, on the left (driver's side), above the valve cover near the rear. Look at the intake manifold pipe where the heater is (it will be a hexed plug with a stud/nut/wire on it, about 1-1/4" dia.), and follow the wire to the relay. On mine, it appears to be a no-brainer, and pretty simple. The manual specifies the only difference between CA and non-CA models is the CA model is part of the glow plug circuit, and the Federal model is independent.