A neighbor has been without the A/C system almost all summer. He hired some local HVAC guys to look at his BRYANT A/C system and they replaced a starting capacitor on the compressor that got the unit working temporarily for that day. They got lucky! The system appears to work intermittently one day and not the other. He came over to ask for help and I really couldn't say no since I have a little experience with odds and ends especially electrical things, I am not an HVAC or electrical expert but I enjoy tinkering with all things. I went and looked at his A/C system and initially discovered that his digital thermostat (honeywell) would blink when we selected a cooler temperature than his inside house temperature which was already 89 degrees. We selected 75 degrees, cool, and auto on the thermostat, one fan kicks in but not the compressor or the fan on top of the radiator looking unit (condenser?). We went to the roof and opened his unit and verified that the compressor is not turning on nor the fan on top. We checked the voltage into the compressor and it was there on all three connections 120vac. We also checked the low control voyage which is 24vac on the top of the contractor I believe. We went back downstairs and tried cycling the system off and on and it worked, both the compressor and the fan started right up and we went back upstairs to verify that it was. We went back downstairs and left it on for a few minutes and thought about this and were really confused, we wanted reliability so we turned it off and tried to turn it on after a few minutes and the system went back to the original none working condition. To try to make it short this happened 3 times on that day, we went upstairs and checked connections and discovered that the wires from the thermostat were spliced outside the A/C unit right on top of the roof and all the insulation was deteriorated from the heat of the roof. We shut off the power and re-did the wiring splice to keep the wiring from shorting each other, then tried it again and the blinking thermostat still kept acting strange. We decided to pull the thermostat and as we were taking the cover off we discovered that 2 wires were off, the yellow and a blue wire. I tired to rewire it exactly as the wires were wired on the thermostat and popped the 5 amp fuse upstairs on the control board. We replaced the fuse and then realized that since the existing wires were so short the person that wired it cut a piece of the blue wire and extended the yellow wire in the wall to reach the thermostat with duct tape and wired the blue piece to the yellow terminal. I figured it out that I did not need that blue wire after popping the fuse and have since replace the thermostat with a newer digital honeywell thermostat and wired the Y-Y, G-G, W-W, and R- RC (with a jumper to RH). After we replaced it it worked well for a few minutes until we wanted to make sure it was reliable and we turned it off then it wold not come on again. So now after checking all the wiring and everything we could think of we are out of ideas. Would the Ignition control board be a possibility? Any Ideas that I can try? I removed the Control board and checked all the components that are checkable with a multimeter and they appear to be okay, nothing burnt. I will be going to his house tomorrow and want to try something beside re-installing the control board. I was going to order parts on the board if I notice a bad relay, resistor, capacitor, or component to try to save him money because I looked up this board and the cheapest one was listed for $287 and as high as $900 from one company.

Hi , have a 3 year old central ac unit. Yesterday I changed the air filter for reg maintenance , that night ac stopped blowing , the outside fan is running but no air flow from vents also noticed some small ice on top of inside ac unit . Could it be related to the new air filter somehow ? What can I try to fix it ?