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not sure how to wire the ac and heater motors
the gray wire is aloop from one connector the other
the right connector is the upper heater fan switch
 

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Looks different that what I have. What year is it? Mine has the AC wiring more or less added on, not inside the wiring harness, even though it's a factory AC car. There's a normally closed relay inline with the heater motor so that when the AC is turned on the relay opens and the heater will no longer work.
 
A grey wire?! Another mystery. Alan, from what I have been able to determine, the heater fan and evaporator fan are interconnected in the 74s differently than other years. There is a wiring diagram that shows this (from D-jetronic) but it is hard to read. If we could get that diagram more focused, it would do you and me a lot of good.
 
I have the blue book, and a scanner, but there's no 74 AC wiring diagram. Are you saying it's mixed in with the fuel injection diagram? I definitely didn't look there.
 
Which diagram are you looking for that you mention is out of focus. I can have a look at what I have and if I have it I can scan at a high resolution and send to you both.
 
Wise9UY:
Here's the attached that's fuzzy. If you can find the diagram and scan it, that would be great.
 

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bill said:
Wise9UY:
Here's the attached that's fuzzy. If you can find the diagram and scan it, that would be great.
Click to expand...

I will look through my factory service manual and see what is in there later and email you. I will scan the pages for the 1974. PM me your email address.
 
I believe that you will find most wiring to be the same. The factory changed wiring colors, but the wiring path is the same.

Have had a few conversations with SFDon... Especially with AC wiring where the wire color itself, is different. The only real difference is in the 4 pin AC switch versus the earlier 3 pin AC switch. The AC will work either way.

It is important to verify that the heater blower bypass relay is a correct "87a" relay.
 
Vern: from what I have seen, my 74 has a radiator temp switch (disconnected/removed by PO) not used in previous years. The aux fan relay is mounted alongside the battery next to the other relays (horn, etc.) not on the right fender. It is supposed to have 5 wires (depending on the diagram) but only has four. There is a main relay between the battery and the ignition (haven't been able to find that yet) , there's a diode in the circuit to the compressor clutch, and all kinds of other goodies that make our 74 wiring apparently unique. Just started matching wire colors with various diagrams I have and so far I'm finding differences. I will have a beer (probably several) and press on until I get this all sorted out.
 
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