I have a AF80 Aire Flo Gas furnace and I would like to be able to run the blower fan continuously on low speed... then when the furnace fires run on high speed... Is this possible with this model?

I did try hooking the G terminal at the thermostat to the G terminal on the furnace panel and the blower ran on high speed... also by moving the black wire from the heat terminal to the cont terminal the blower ran at high speed...

Thank you