My inside blower has an intermittent problem. Sometimes when the outside unti turns on the inside blower will not turn. You can turn the temp up on the thermostat to make the outside unit turn off, let the unit equalize and then turn the temp back down and the inside blower will turn on. I have also tried turning the fan to the on position when it acts up but the fan will not turn on. This may happen once or twice a day or maybe every couple of days. There is no set time of day or night this happens. It will always come back on after reseting the temp. I have changed the thermostat with no success. Could this be in the control board or possibly the fan relay. The biggest problem with doing tests is you will have to remove the panel when it acts up which makes you have to leave the outside unit running while removing the panel which in turn freezes the coils up. How do I proceed?

It sounds like a blower relay sticking(not closing all the way due to dirty contacts inside the relay) if the blower is not running when you call for cooling turning the fan switch off and on at the T-stat will not do you any good the relay is already energized from the call for cooling, but when you turn it off from cooling and then back on the relay breaks contact and then tries to make again getting better contact. If it's a simple relay system its easy to replace and a cheap part.