52 Chevy heater

I just bought a 52 Chevy Hardtop and I'm trying to get the heater working. There are three levers. Can anyone please tell me how the heater controls work meaning what lever does what?

Thanks

 

all the way to the left is the blower motor switch, middle is defrosters and heat temp is on the right which turns the nozzle to let the antifreeze flow through the heatercore, on some of mine the pull cables that operate them are seized and dont work so i manually have to turn them on. im not sure which switch opens the valve to let the hot heat in it because thats whats the cable is frozen on mine. oh mines a 51 chevy but i think theyre the same

 

I took the controls out last night and learned a lot. The left switch that controls the fan also works the cable to open or close the flapper air valve in the firewall to let air into the blower motor. It was also frozen on mine. I took the cable out and after some WD 40, I was able to remove the cable from the housing and clean it up with some sand paper. I then greased it and reinstalled in the housing. Works great now.

Joe

 

Heres a pic