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Discussion Starter · #1 ·
I added AC to my 66' using the Old Air Kit but I purchased an OEM AC Evap/Blower unit to go with it. I have everything hooked up except for the 12vdc wire. I looked at some wiring diagrams and it appears from the schematic that it connects to the yellow wire on back of the ignition.

I was wondering if anybody knew of another source that would work good to supply 12vdc switched power to the AC unit? I'm trying to avoid blowing any fuses or effecting any other components using 12vdc switched power, in the event there is more draw for the AC blower unit.
 

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I just hooked up an Old Air system in a 65. I used the power off the back of the ignition switch as Ford originally did. The Old Air system had an in-line fuze. Ford used and inline 15 Amp Fuse.

The best option would be to use the accessory feed to drive a relay that sends power from the battery to the A/C. You would still want in inline fuse though.
 

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The YELLOW wire is hot all the time, not switched. I'd avoid that one.
The BLK/GRN is the "accessory" feed and will be HOT in "ON" and "ACC". This is where the factory A/C unit was connected, with a 15 amp in-line fuse. It is the "A" position on the ignition switch plug.
 

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Discussion Starter · #4 ·
The YELLOW wire is hot all the time, not switched. I'd avoid that one.
The BLK/GRN is the "accessory" feed and will be HOT in "ON" and "ACC". This is where the factory A/C unit was connected, with a 15 amp in-line fuse. It is the "A" position on the ignition switch plug.
I'm so glad I asked. I think I spotted two of those Blk/Green wires under the dash but for some reason I thought they were for headlights or fog lights.

Thanks.
 

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Discussion Starter · #5 ·
I just hooked up an Old Air system in a 65. I used the power off the back of the ignition switch as Ford originally did. The Old Air system had an in-line fuze. Ford used and inline 15 Amp Fuse.

The best option would be to use the accessory feed to drive a relay that sends power from the battery to the A/C. You would still want in inline fuse though.
Thanks! That's where I'm going to hook it up at then. My Old Air just came with two wires, one to the pressure switch and then one to the evap/blower, there was one wire left coming off the evap/blower assembly to hook up to power.
 

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Discussion Starter · #6 ·
The YELLOW wire is hot all the time, not switched. I'd avoid that one.
The BLK/GRN is the "accessory" feed and will be HOT in "ON" and "ACC". This is where the factory A/C unit was connected, with a 15 amp in-line fuse. It is the "A" position on the ignition switch plug.
So I finally got around to hooking this wire up when I was putting in the seats...that way I could lay down and look under the dash. With the wire hooked up the ACC, the fan comes on when the key is in ACC or ON. But it doesn't change speeds when I turn the dial 1,2,3. I read the voltage with my voltage meter and I am getting 12.4 vdc at the hot end. Then to test further I ran a hot lead from the battery and hooked it up the AC hot lead. Turned on the dial an the fan spun harder/faster than when hooked up to the ACC. I measured the DC voltage and it was like 12.6 (no voltage drop) since it was coming straight of the battery. However the dial on the AC unit still didn't change the speed when I switched between 1,2,3 on the selector. Do I have a bad AC fan speed switch?
 
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