My HVAC Blower fan stays on even when I remove the thermostat face plate (with the fan in the auto position and the thermostat in the off position). I have tested for a short in the thermostat wire and there doesn't seem to be one.
The backstory... We bought the house and everything worked until we turned turned the heat on... Turning on the heat blew the 3 amp circuit in the blower housing. I had an HVAC guy come out and he found 3 issues... There was a short in the wiring between the Thermostat/control board/and the overflow shutoff for the evap pan below the unit. He fixed the short, rewired the thermostat (which he said had no common, but I am looking at the schematic for it now and it looks like it does has a common and is a Honeywell Model #RTH111B1024, which is as basic a thermostat as you can get. I do not know exactly what he did, but he got it working. That was in early January 2021. The HVAC guy was very good and said he had wired a few of these last summer when he could not get regular thermostats and he had to use ones from Home Depot that had no Common, so he already knew the fix...
Fast forward 8 months (August 30, 2021 - almost Labor Day 2021) and the fan runs even with the thermostat in the off position and the fan in the Auto position... it also runs when the thermostat faceplate is removed. Here are my collection of images. Any advice would be appreciated.
I believe the relay next to the transformer is might be stuck, but I am a novice at this, so please have patience with me (see lower left quadrant of the wiring diagram shows the relay that I believe is in need of replacement. I am not sure how to test it yet, but will do some searching on this tomorrow. I have my doubts about the wiring of the thermostat... The wiring in the house is very suspect. I had a few outlets wired backwards and a few that had the ground wire wrapped around the pole, but not screwed in. I have checked every one and found 3 such unscrewed ground wires, 2 wall outlets installed backwards (the hot and return switched). I imagine the same guy who left the HVAC with a short above the air handler (see the second pic) did the wiring in the rest of the place?