Hi,
When my blower for my heat/ac is working fine when I have it on heat (from the furnace) but when I switched the thermostat over to cool the cool air came out but wasn't forced i.e. the blower doesn't start up? Any ideas anyone? Thanks a lot.:confused:

In your no brand name no model number unit there should be a relay that activates the indoor blower motor in the A/C mode. You will need to find the relay and test it if possible. You may also test the green wire that comes from the thermostat to the air handler/furnace to see if voltage is being supplied from that green conductor to the air handler/furnace low voltage wiring/terminal strip.