Armstrong AC wiring diagram

[Lumatic]

There are 4 wires going into my 1975 oem Armstrong Air Conditioner wall mounted thermostat: green, red, black and brown. The red seems to be the + wire. I need to figure out the others. Anyone have a wiring diagram? Any suggestions on a Air Conditioner wall thermostat replacement?
Thanks
Marshall

[mopariac]

Hopefully this will help. The diagram shows a white wire instead of the brown but would have to think they would go to the same place on yours...hope it helps.

Tharon

[Lumatic]

This is the sucka. more to follow

[Lumatic]

Photo 2

[Lumatic]

[Lumatic]

Maybe this will ring a bell for someone. These are the labels on the thermostat shown in the last photo above:

The green wire goes to a connection labeled G!
The black wire goes to a connection labeled G2
The brown wire goes to a connection labeled Y
The red wire goes to a connection labeled R

G1 is on the left side of the thermostat. G2, Y and yellow are on the right side. My problem is figuring out what functions on the thermostat do these connections relate to. The wiring diagram ABOVE shows these wires, but I can't figure out what they do or what switch they are connected with as the circuitry is hidden.

At the bottom of the thermostat are 2 switches: on the left LO/ HI (Fan) on the right COOL/ OFF

[Dave.K]

Im working on the same thing to day. Here is what I found. Brown wire to the Y.
Red to R, green wire is low fan speed , black is high speed. green or black go to
G on thermostat depending on speed you want.

[Lumatic]

Originally Posted by Dave.K

Im working on the same thing to day. Here is what I found. Brown wire to the Y.
Red to R, green wire is low fan speed , black is high speed. green or black go to
G on thermostat depending on speed you want.

So red is +?
What does brown/yellow do?
Does the circuitry switches combine both black and green to give you high or would that fry the wires?

[Dave.K]

Ok Yes Red is + that goes to red on your new thermostat . The Brown goes to the Y on the thermostat . green or black do not wire them both together. Depending on the speed you want the fan to run. On mine black is high speed. I went manards & bought a cheep lux thermostat for $15.00 works well.

[Dave.K]

Sorry I forgot to tell you brown turns on the compressor .

[Lumatic]

Originally Posted by Dave.K

Ok Yes Red is + that goes to red on your new thermostat . The Brown goes to the Y on the thermostat . green or black do not wire them both together. Depending on the speed you want the fan to run. On mine black is high speed. I went manards & bought a cheep lux thermostat for $15.00 works well.

So with your cheep lux you only run your fan on high? No high/low fan switch right? Is your $15 thermostat a furnace thermostat? Or a "close on rise" thermostat meant for AC? If it is a furnace thermostat, (if I am understanding the difference between AC and furnace thermostats) it sounds like it can only be used the turn the AC on manually. Sounds like with a furnace thermostat the AC won't automatically shut on and off in relation to temperature, automatically turning on when the temp gets too high and automatically shutting off when the temp gets too cold?

[Dave.K]

It is a normal home thermostat that runs heat & A/c you have to chose high or low speed when you wire it . It works just like in your home it should shut off on it own. Turn it to cool & set your temp. If all else fails call an A/c repair company & have them wire it.


Good luck

[jmpratt]

If you look at my posted pictures, I've included an entire Armstrong manual. It has a wiring diagram. I don't know if its your model, but it might help.