OldIHC

hello on my kb-3 it have 3 wires on cab heater.. 3 speed or??? thank's

If it has the "barn door" heater, it is two speed, forward and reverse. You reverse the four blade fan to draw air thru and feed the hottest air to the squirrel cage blower for the defrost, turn it forward to put more heat into the cab, the defrost works with the motor running in either direction.

If it is the original fan motor on the barn-door style heater it would have 4 wires, not counting ground wire screwed to the heater assembly. It is entirely possible the fan motor was changed at some point to a different one

picture would help,

hello i removed entire cab heather and really 3 wires two speed and a ground + one ground connec to frame at exit of wire on unit motor and the motor is not running. I dissembly it and i will répair and it is a two speed and double fan, one defrost et one cab heather.. thank's..

sounds like you have a replacement heater someone installed later on, an original one would not have two fans,

The barn door heater has two fans and one fan motor, one paddle wheel and one squirrel cage blower driven off a common shaft.

Probably looks like this fan.

I consider that one fan myself, I take two fans as 2 Separate fans, but everyone sees differently, so sure a KB heather has 2 fans in one.

http://www.hotrod.com/articles/1108clt- ... c-pickups/

Can something like the Vintage Air heater be hidden inside an original heater case?
yes. I don't know why you would. the Vintage Air unit is so small it can be almost out of sight. I installed the Vintage Air Mini-Space saver in my "R" The VA unit was not easily visible and the Mini space save is 4 times larger.