2005 Honda Civic Hello Car 05 Lx Mechanic Trying Figure Out Which Relay

Hello! My car is '05 HONDA Civic LX. My mechanic is trying to figure out which relay is connected to the heater. I am referring to the four relays installed by the heater blower motor under the glove compartment: (Honda parts #) 39794-S04-014Relay Assy., Power (4p) (Micro Iso), 39794-S5A-003Relay Assy., Fuel Pump (5p) (Mitsuba), and 39794-S5A-901Relay, Pcm (4p). Two of them are black, one is orange, and the other one is blue. I would like to know which one is related to the heater. Thank you very much!