What does this thing do?

[taxlex 10]

Does anybody know what this is?

It is under the dashboard. It says Ford on it.

The speedometer is hooked to it and it connects to a white box with a blue cover. It could be cruise control but there is nothing under the hood connected to to the carburetor. Is it stock or did somebody add it later?

 

[tim42 13]

It's part of a factory cruise control. It is the speed sensor. The cable that goes to the transmission is missing. There should also be a vacuum canister somewhere and if manual a electric switch attached to the clutch pedal and there should be a vacuum dump switch on the brake cable plus the cable that attaches to the carb and vacuum can. Basically it is part of a cruise system and there are parts missing.

[zudman 11]

Looks like one of the parts for the Distributor Modulator..Have no idea what it does, mine had it I removed all but the switch that goes in the door jam just to fill the hole..

[miketyler 15]

That would be my guess as well with the modulator box there in the background.

[1969vert 55]

Cruise control box...had one like that on a 70..

[1969vert 55]

Do you have the button on the end of the turn signal stick?...like the cougars used?

[indianfiremach 170]

Cruise control box...had one like that on a 70..

 

 

No cruise available in 1970, ford stopped offering it as an RPO after 1969. That box is for the Distributor Modulator system.

 

Copied and pasted from Don Rush's website:

 

The purpose of the distributor modulator system was to help reduce carbon monoxide and hydrocarbons.

 

Distributor modulator system was standard equipment on some 1970 Ford Mercury Lincoln vehicles. We see it only on the 1970 Mercury Cougar and Ford Mustangs with the M code 351-4V Cleveland engine and FMX automatic transmission.

 

The purpose of the distributor modulator system was to help reduce carbon monoxide and hydrocarbons. Sometimes it is referred to as the Dist-o-vac system. The basic premise of the system was to use carburetor venturi vacuum to reduce engine emissions. This was performed by controlling distributor spark advance. A retarded spark provides hotter combustion chamber and exhaust manifold temperatures that cause more complete burning of the fuel.

 

The three main components are the Electronic Control Module, Speed Sensor, and Thermal Switch.

• Electronic Control Module is the black box which houses the PC board and solenoid valve. Ford part D0AF-9E718-S, in the manual it is described as having a black box and a blue cover, we also see them with black covers on the black box.

  
  

  
  

  *Side note – There is also a white colored box along with black, blue, and white covers. This combination of boxes and lids make for 6 differently identified units for a range of other applications.

  
  

• Speed Sensor this actually is often confused with a cruise control part. It mounts inline on a two piece speedometer cable, it also has a two wire plug coming out of it. Ford part number D0AF-9E731-A.

  
  

• Thermal Switch this measures temperatures and only engages the modulator system on, at temperatures above 58°F. Ford part number D0AF—12A164-B.

  
  

For a 1970 Mercury Cougar or Ford Mustang the black module box will 'cut in' at speeds of approximately 23 mph and 'cut out' when speeds fall below 18 mph, provided that ambient temperatures are about 58°F.

[Jimjific 23]

indianfiremach,

 

Thanks for the info. I had a 70 Mach 1 years ago and it had one of those and I always wondered what it was. One interesting thing though, my Mach 1 was a 351C 2V with an FMX.

 

Jim