The old McQuay unit vents came in many different flavors, a 500 cfm, 750, 1000, 1250 and 1500 and a 2000 cfm ceiling mount horizontal model. They also came in a wide array of heat/cool and economizer options. I can't make heads or tails of the model no. Do you have any idea which specific unit you have? They are easily identified by the cabinet length and number of fans. If memory serves they had a transformer that sometimes had 10 or 15 different speed taps.
I might be able to point you in the right direction to find a generic diagram for your unit.
The picture in my avatar is of the Houston Ship Channel and was taken from my backyard. I like to sit outside and slap mosquitos while watching countless supertankers, barges and cargo ships of every shape and size carry all sorts of deadly toxins to and fro. It's really beautiful at times.....just don't eat the three eyed fish....
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