duo-therm a/c does not start

I just came in from trying to further diagnose the issue. I did remove the tstat from its mount and there is no fuse in it as dougrainer said. I rechecked all of the breakers in the AC distribution panel as well as all of the other power centers including the main 12V and under the hood. Nothing appears to be wrong there. I also accessed the underside of the front A/C unit above the filter grille and found a 3A fuse but it was not defective. The rear unit works well on all settings so I am frustrated that there is not at least a fan working on the front. I tried it on both the GEN and 110V today with no result. I will get up on the roof tomorrow to see if by chance that the fan is not able to turn. Is there a way to check the incoming power there to determine if its somewhere up the line before the A/C unit?