Make sure power is off.

Unscrew the old transformer and leave the wires attached, so it dangles down some.

Now screw the new one in the spot old one was mounted.

Now identify your 2 high volt wires from the old transformer and cut them both.

Now attach the high volt wires you just cut to the high volt wires of the new transformer using permanent wire nuts . (Note: Read the new transformers tag to verify which 2 color wires are for 115 volts input.)

Now cut the 2 remaining wires going to the old transformer ( 2- 24 volt wires ) and connect them with permanent wire nuts to yellow and blue from the new transformer.

Now put your amp probe on one of the high volt wires going to the transformer.

Set your meter to AAC so we can watch how many amps the transformer pulls when we give it power.

(Note: If your transformer pulls over 1.0 amps you need to kill power and find your electrical short or ground. I suggest taking off 1 thermostat wire at a time and re trying unit every time till you see that your short is gone amp draw drops and then you have identified your bad wire.)

If the transformer puts out 24 volts and pulls less than .999 amps your ok to leave it be.

Nice Job your done, you just fixed your air conditioner.

Move to end test page to verify your temperatures. This will tell you if its really fixed or not.

You be sure to tell all your friends about the matrix.