There are several issues her. Last one, if they sold you a starter for the wrong application , its on them. Two, the glow plug solenoid looks identical to a standard Ford starter solenoid. Starter relay has a large copper disk pulling against 3/8 bolt heads in relay. the glow plug has a contact the size of a #2 pencil eraser. When the glow plug relays dies use starter solenoid/ relay ,same thing). About 1989 I had to replace the glow plug contactor in my 86 trk. It still runs and when it wears out I will replace it .. I am the original owner of my truck, spec it and waited two and a half months for it to be built and delivered. had less than ten miles on it when it went to Ziebart.