A/C electrical short?

I have a 1987 with manual a/c. Everytime I turn on the a/c the 25 amp fuse blows. I have torn the entire dash apart and cannot find a short. I have unplugged everything I can to eliminate things but still as soon as you switch to a/c or defrost it blows the fuse. If you select heat or vent with the key off then turn on it works fine. If I take the fresh air door wire out of the plug and plug back to the switch it works fine. I know this is where my problem lies but I'm not sure where to go from here. Has anyone else had this problem?

Chris Trautman @ Corvette Assembly Plant 2019

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