1967 Mustang Wiring and Vacuum Diagrams - Average Joe 1967 Mustang Wiring and Vacuum Diagrams. March 10, Switch, blower motor and resistor . 1967 Mustang Air Conditioner. my 67 mustang has no pressure switch on it. does the thermocoupler control compressor dean — June 15, 2012 6:12 AM . this has been a lot of help thank you Mustang Heater Blower Motor Wiring - Search the Virginia These wiring harnesses are made to replace the damaged original wiring coming out of your Mustang's Heater Blower Motor case. They feature the correct colors, connectors and grommets. The earlier (production before 4/1/65) style features the orange, red and black wires for the 2 Speed (3 wire) motor.