Shadetreemechanic
Full Access Member
The main wiring difference with the older screw in controller is it uses a separate solenoid on the passenger fender to actually engage the glowplugs. The later solid state connector has the solenoid integrated into it so all the wiring is together.
I bought the accurate diesel "upgrade" for my 86. It lasted about three years and maybe 60 k miles. It did fail in the off position. The original one would often fail in the on position and burn out your glow plugs. Because the older system has a separate solenoid, its super easy to mount a momentary in the cab to accurate the glowplugs and you can have both systems at once. I have had a NOS motorcraft controller now for several years, but I have never gotten around to installing it. The momentary switch works fine.
I bought the accurate diesel "upgrade" for my 86. It lasted about three years and maybe 60 k miles. It did fail in the off position. The original one would often fail in the on position and burn out your glow plugs. Because the older system has a separate solenoid, its super easy to mount a momentary in the cab to accurate the glowplugs and you can have both systems at once. I have had a NOS motorcraft controller now for several years, but I have never gotten around to installing it. The momentary switch works fine.