I am also curious to know if your indoor blower control through your thermostat operates your a/c outdoor unit.
Here is why I ask. Your thermostat wiring having 2- reds, 1 on RC and 1 on RH usually indicates 2 separate 24volt power supplies, one from the outdoor condensing unit and one from your heat source, boiler, furnace etc. As the Airheatman indicated if there is a jumper between RC and RH then its only one 24 volt supply.
As stated above the Y terminal controls the cooling at the thermostat, the G terminal controls the indoor blower and also makes when the Y terminal makes.
So not having a wire on Y indicates that the cooling circuit is probably being made through G.
If you have a switchable subase (an optional component) it will have two switches
1 will be fan + auto this allows you to let the fan (indoor blower) cycle with the cooling, or you can operate just the fan continuously by selecting on.
The other switch is cool, off, and heat it allows you to switch between heat and cool.
If you do indeed have a switchable subase, switch the fan to on and see if the outdoor condensing unit operates, it will operate if it is wired through the fan circuit of the subase regardless of temperature setting or mode selector setting.
If this is the case, it will work, but is not right and should be corrected as it could cause a failure of your compressor.
Also if you could share with us how your son solved the problem it would be greatly appreciated.
Stay cool and thank you.