PART ONE
Mass Air Conversion

The following is taken from Interactive Systems Technologies kit instructions for mass air conversion. This applies generally to Ford Speed Density EEC-IV cars.





Included are the wire colors, except for the 4 mass air meter wires. The kit contains a 4 wire harness with colors as listed below. The stock Ford (i.e. Mustang) mass air meter harness may or may not have the same wire colors.

** Shows wires that are Lincoln specific and should remain in the same position.

• The White / Red Thermactor Air Bypass Solenoid wire (AM1) on the SD pin #51 must be moved to pin #38 on the MA computer.
• The Light Green / Black Thermactor Air Bypass Solenoid wire (AM2) on the SD pin # 11 must be moved to pin # 32 on the MA computer.
• ** If there is a Dark Green / White Vehicle Speed Sensor wire (+) in pin #3, this should remain in the same position (this connects to the vehicle message center). If there is not a wire in pin #3, one should be installed from pin #3 and spliced into the hot wire to the Vehicle Speed Sensor at the back of the transmission (may be Dark Green / White)
• ** If there is a Purple / Light Blue Vehicle Speed Sensor wire (-) in pin #6, this should remain in the same position (this connects to the vehicle speed sensor). If there is not a wire in pin #6, one should be installed from pin #6 and spliced into the ground wire to the Vehicle Speed Sensor at the back of the transmission (may be Orange / Yellow or Purple / Light Blue)
• Main Power (Vehicle Power) to the MA meter must be spliced into pin 37 or 57 on the MA computer.
  This is a Red Wire in the kit MA harness.
• Main Ground (Power Ground) from the MA meter must be spliced into pin 40 or 60 on the MA computer.
  This is a Black wire in the kit MA harness.
• Signal Ground (Mass Air Return) must be installed into pin location #9 on the MA computer.
  This is a Brown wire in the kit MA harness.
• Signal (Mass Air Signal) must be installed into pin location #50 on the MA computer.
  This is a Blue wire in the kit MA harness.
• Pin #19 is the fuel pump run monitor. It must be installed from pin #19 on the MA computer to a Pink / Black wire behind the left kick panel.
  This is a new wire that must be installed.

1988 - 1992 LINCOLN LSC SPECIFIC: The following Integral Cruise Control wires to the SD computer should be removed from the plug and taped up as they will not be used in the MA computer. Wire #39 needs to be grounded to make the horn operate. (You may use them to hook to the SD computer to retain computer operated cruise control).

• Pin 2: Brake ON/OFF. . . . . . . . . . . . . Light Green
• Pin 35: Speed Control Vent Solenoid. White / Pink
• Pin 38: Speed Control Vacuum Solenoid. . . . . Grey / Black
• Pin 39: Speed Control Command Switch Ground. Light Blue / Yellow
• Pin 41: Speed Control Solenoid (+) . . . . . . Orange / Yellow
• Pin 50: Speed Control Command Switch (+) Light Blue / Black

PART TWO
Cruise

This was taken from an article on the internet written by Julian Homan. It details how to retain computer controlled cruise control when converting to mass air for vehicles that originally have the cruise control integrated into the computer.





This is an alternative to purchasing the stand alone cruise control servo control box that mounts under the steering column and attaching wiring harnesses and plugs. This will likely be somewhat cheaper as all you need is another computer plug and some wire pin sockets (get them with the plug from a junkyard). It also avoids having to remove and replace the cruise control servo and hooking up the control and wires under the steering column. It does require splicing into several wires leading to the mass air computer which is not a simple task because of the difficult access and large number of wires in a small area.

The author mounted his SD computer in the glove box and ran the wires thru the bottom of the glove box and over to the existing engine harness. I didn't want to lose my glove box, so installed my SD cruise computer under the passenger side of the rear seat. There is a cavity under the seat cushion where it fits very nicely. I ran the wires under the edge of the carpeting, along with a bundle of existing wires, by the sill plate by the passenger door. Look very closely at the wire side of the computer plug - very tiny wire numbers are molded into the plug.


Materials you will need:

Computer plug and 9 wire sockets to hook into the computer plug. Virtually any Ford vehicle with EEC-IV has the same computer plug, although the wire colors will be different. Prices may range from $5 to $20 at a junkyard. Just cut the wires as far up from the plug as you can access - that way you'll have extra wires with pin sockets already factory crimped. ABSOLUTELY solder and tape all connections and splices! These signals are low amps/volts and must have good connections. Also, solder connections do not corrode and fail like crimp connections. Use heat shrink for end to end connections. For splicing, remove the insulation from a short section of the wire you're splicing in to, being careful not to cut any strands of the wire itself. Wrap the end of the wire you splice around the bare section, solder, and wrap well with tape.

These wires are removed from the SD computer during the MA conversion. They can be hooked into the original SD computer as the MA computer doesn't use them. They should be connected to the SD computer on the same pin number as they were originally installed.

• Pin 2: Brake ON/OFF. . . . . . . . . . . . . Light Green
• Pin 35: Speed Control Vent Solenoid . . .White / Pink
• Pin 38: Speed Control Vacuum Solenoid. . . . . Grey / Black
• Pin 39: Speed Control Command Switch Ground. . . Light Blue / Yellow
• Pin 41: Speed Control Solenoid (+) . . . . . . Orange / Yellow
• Pin 50: Speed Control Command Switch (+) . . . Light Blue / Black

These pins / wires should be spliced into the original EEC harness wires and connected to the SD computer. DO NOT disconnect them from the MA computer - they MUST REMAIN CONNECTED to the MA computer.

• Pin 1: Keep Alive Power. . . . . . . . . . . Black / Orange
• Pin 3: Vehicle Speed Sensor (+) . . . Dark Green / White
• Pin 6: Vehicle Speed Sensor (-) . . . . . . . Purple / Light Blue
• Pin 20: Computer Case Ground . . . Silver Stranded or Black
• Pin 30: Neutral Drive Switch (neutral safety) . . . White / Pink
• Pin 37: Vehicle Power . . . . . . . . . . . . . Red
• Pin 40: Power Ground . . . . . . . . . . . . . Black
• Pin 57: Vehicle Power . . . . . . . . . . . . . Red
• Pin 60: Power Ground . . . . . . . . . . . . . Black

(Wires for the Cruise on the SD computer, listed in numerical sequence)

• Pin 1: Keep Alive Power. . . . . . . . . . . Black / Orange
• Pin 2: Brake ON/OFF. . . . . . . . . . . . . Light Green
• Pin 3: Vehicle Speed Sensor (+) . . . Dark Green / White
• Pin 6: Vehicle Speed Sensor (-) . . . . . . . Purple / Light Blue
• Pin 20: Computer Case Ground . . . Silver Stranded or Black
• Pin 30: Neutral Drive Switch (neutral safety) . . . White / Pink
• Pin 35: Speed Control Vent Solenoid . . . White / Pink
• Pin 37: Vehicle Power . . . . . . . . . . . . Red
• Pin 38: Speed Control Vacuum Solenoid . . . . . Grey / Black
• Pin 39: Speed Control Command Switch Ground . . . Light Blue / Yellow
• Pin 40: Power Ground . . . . . . . . . . . . . Black
• Pin 41: Speed Control Solenoid (+) . . . . . . Orange / Yellow
• Pin 50: Speed Control Command Switch (+) . . . Light Blue / Black
• Pin 57: Vehicle Power . . . . . . . . . . . . Red
• Pin 60: Power Ground . . . . . . . . . . . . . Black

- macx