Have you chacked your A/C breaker, 110 VAC. I believe you have a 12 volt relay that starts your A/C. That might be the ticking sound. Do you have 12 VDC at the thermostat? Now I don't know much about the A/C but this will give you a starting point to look at until someone with the knowledge replys.
1997 Triple E Empress, Freightliner Chassis, CAT 3126 w/ 275 horse's.
MD 3600 Tranny, 2011 Ford Escape Hybrid w/Blue Ox tow bar and Roadmaster Base Plate.
Amsoil Synthetic Oil only for my baby.