Hvac Schematic

AC unit comes on, but fan doesn’t blow?

The AC unit at a house I’m working on comes on when the “cool” option is selected on the T-stat, but the fan doesn’t come on. The fan comes on with the heater just fine, and comes on with the “fan only” option on the T-stat, but not with the “cool” option. All these functions work from the T-stat. When I get up in the attic unit, I can see 22V across the C and G terminals and the C and Y terminals when the T-stat calls for the AC unit. From what I understand, the G terminal is the fan and the Y terminal is the AC unit from the T-stat. The oddest thing about this problem is that all the components work, and the all work together except for the AC and fan. I am an electrician by trade, but not too experienced in HVAC. I can read a schematic and have a decent understanding of all the troubleshooting methods except when it comes to the control board. This seems like a missing jumper or something else very simple. How can I fix this cheap and easy?

If there is a cooling fan timer, check for 24V there. If not, sounds like a bad T-STAT.

CATIA V5 – HVAC Schematic to Design (HVE)