Shown below are the terminal positions typical wiring colors and usage. The system on page 62 was a trinary switch operated system which means the condenser fan and the fan clutch are only on when the head pressure is high enough to close the switch.
Pac 2750 Fan Controller Amp Trinary Switch The 1947 Present
Trinary switch wiring diagram. You may still need a kenworth diagram but the manual will help you identify what kind of switches you have. Trinary switch wiring diagram. In the vintage air diagram you will see that the blue wire on the trinary switch is used to ground switch the coil of the cooling fan relay. Also below is the internal schematic for each of these switches. Four seasons trinary switch part numbers are 35889 and 35901. Vintage air 18865 goll st.
Trinary switch blue blue blue. Because you have a trinary switch the ac relay setup they show in their diagram is unnecessary. Trinary switch wiring diagram. San antonio tx 78266 p. W kenworth ac wiring diagram ci2t together with watch in. These are listed below.
If the original trinary switch terminals are different a four wire boot connector part number 35900 can be used. Jan 13 i was looking at the wiring diagram for your radiator fans on the be cool website. Ford or gm pcm with power lead for engine cooling fan 30 85 86 87 87a blue blue red red red purple white white black ground battery auxiliary blue 12v key on ignition source 12v battery or ignition source pcm cooling fan power lead blue blackgreen dark blue blackgreen. 1 pac 2750 module 1 rly 3 relay with wiring harness 1 bim data cable 1 bim xx 2 adapter harnesses 1 instruction manual for some options of the pac 2750 additional components are required. Terminal 1 black wire. Dakota digital pac 2750 man 650411d pac 2750.
Using a trinary switch can improve system performance extend the life of the radiator fan and in this case simplify the wiring substantially. When the pressure of the refrigerant in the system exceeds the set point of the trinary switch it will close its contacts and connect the fan trigger to ground.
Gallery of Trinary Switch Wiring Diagram
