I took this from a u pull it the other day. Came from a 1978 or 1979 2wd auto f250 I believe that had factory cruise. It was under the dash next to the cruise control amplifier. Anyone know what it is?

 

Looks like an intermittent wiper module.

 

Okay, are you ready for this one?
It's an "Emission throttle positioner control actuator assembly".
Part number D5HZ-9F441-A, marked D5FH-9F441-AA or D7HF-9F441-AA

 

OK then!! Now, the million dollar question, what was it's purpose? to minimize a heavy foot on throttle.

 

Absolutely no idea. My guess, emissions related. Yes, I'm being a smart a$$ .

 

Your question got me wondering, what does it do? So I looked at the wiring diagrams.
From the looks of it, that box controls the carb bowl vent solenoid and the throttle kicker solenoid.
It's all laid out on page three of the '79 wiring schematics, upper right hand corner.
The location of the actuator is D15 on the schematic.

 

Looked in my shop manual, (I don't have a wiring schematic) and didn't find it. I guess itwillgo in the box labeled 79 parts.