Outside AC Unit Won't Turn On? What to Do Before Calling Apr 15, 2015What to Do Before Calling for Repairs. April 15, 2015. If there was a power surge, your air conditioner might have blown a fuse or tripped a circuit breaker. At the shutoff box near the AC — Some models of air conditioners have a fuse at the shutoff box. Try replacing this fuse.Air Conditioning · Repair & Maintenance Fuses | LennoxPROs Pick up fuses and additional electrical components at LennoxPros.