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Hello,
Hoping for some wisdom related to Air Conditioning relays.
For context, I am adding back air conditioning to an original A/C car that had all A/C components deleted previously. Compiling a list of parts needed I can find multiple references to an Air Conditioning Relay that is described as operating the A/C magnetic clutch and a Heater Blower Motor Relay that is described as operating the high speed blower motor. It makes sense to me that there are separate relays for the A/C clutch and the blower motor as they can operate independently of each other, for example; the blower can be on high for heat without the A/C clutch engaging. My problem is that when I examine the AIM for 72 and the 56 - 82 Parts and Illustration Catalogue there is only a reference to a single Blower Motor Relay with p/n 1115881 as you can see in the screen cap below. My question is multi-part... Is there a separate A/C Clutch and Blower Fan relay or only one? If there are two physical relays where does the A/C Clutch relay mount as the AIM only shows the location of the Blower Motor Relay on the Evaporator Box? Alternately, if there is only one relay as suggested by the AIM, how is the A/C magnetic clutch operated?
The gold-colored relay (3) in your diagram is only for fan blower speed. On an AC car the fan switch on the console controls the blower speed via the resistor on top of the AC box. In the high-speed blower setting on the console it operates the gold relay (3) which receives power on the orange wire (with 30amp inline fuse) from the Horn Relay on the driver side. The AC compressor is turned on via a switch on the AC control on the center console.
The diagram I am including was made for a 69, but it is basically the same until 72.
The gold-colored relay (3) in your diagram is only for fan blower speed. On an AC car the fan switch on the console controls the blower speed via the resistor on top of the AC box. In the high-speed blower setting on the console it operates the gold relay (3) which receives power on the orange wire (with 30amp inline fuse) from the Horn Relay on the driver side. The AC compressor is turned on via a switch on the AC control on the center console.
The diagram I am including was made for a 69, but it is basically the same until 72.
Thanks Robert, now I get it. The compressor on switch in the controller is sized to directly handle the amperage the clutch pulls without the need for an additional relay. That's a very useful diagram, I'm going to keep it for future reference. It laid out in a way that makes the circuits easy to follow. Thanks again!
A/C Relay Confusion
