AboutHoward Livingston Expertise Can answer questions on electrical control circuits, power supply,airflow & distribution, electrical components,refrigerant problems,gas, electric & propane furnaces.No boiler or refrigerator or oil fired furnaces experience.Just HVAC questions please.
Experience 35 years experience in residential & light commercial repair & installation.
Question QUESTION: Everything (heating or AC) was working before. I turn on AC this year, control board fuse always blow out. Test heating it is working fine. Replaced control board, still can't fix the problem. Thanks, Steve.
ANSWER: That fuse blowing indicated a short in your control system.Can be a shorted coil in the contactor. Need to find it. Can be a dog in the back yard chewing on the wires.
---------- FOLLOW-UP ----------
QUESTION: 1. Checked all wire are good.
2. Replaced contactor.
The fuse is still blowing. Could be other problems? Thanks, Steve.
Answer Now its getting wilder Steve. I would disconnect the 2 wires to the outside unit at BOTH ends. With all 4 ends separated ohm between 2 wires at the same ends. If you have any ohm reading the wires are touching somewhere. That can be caused by a mouse in the attic chewing on them. Next. look behind the circuit board for hot spots. Gotta find it.
