Should your heat/A/C blower motor run all the.

Is there a way of running the power for it it through a relay to where it will only come on when your'e calling for heat, cool, or vent? Or maybe modifying the relay that controls it now?

Well yea, but I don't want to be drilling holes in my dash or somewhere to add a switch that doesn't look like O.E. I guess what I was looking for is can the power that feeds the relay now be moved to a power sourse that would only run when the unit is calling for heat/cool/ or vent, or does that relay have to have constant power for other reasons? Or, can I add a relay to break the purple wire feeding the motor, but I'm not sure how to control the coil fo the new relay.