My original heater switch in my '41 International would change the direction on heater motor. Forward/heat, Reverse/defrost. Was this common on older vehicles and do other makes use this type? I am looking for a switch that will perform the task.
A three pole toggle switch should work (on-off on) Wired right it would reverse the polarity the motor.
A three pole will work IF the heater motor has a double-wound field winding. If not, then you'll need a 6-pole two position, because you need to change the direction of the magnetic field in the armature as it relates to the field windings. Do you have a wiring diagram, or a picture of the original switch? How many wires are coming out of the motor?
Now, you'd need a second switch (in series) with different resistors to slow speeds from full speed. DD
I have no pics,,I was hoping these switches might have been common to other makes. The original 6 volt heater motor has been replaced with a 12 volt motor of the same size. I get lots of heat and believe me I need it up here but as yet no way of defrosting windows. A small recirculating fan mounted in the cab is a temporary solution.
you can always do something like I did. Maybe this will help you come up with a different solution? hope it sparks some ideas! http://www.jalopyjournal.com/forum/showthread.php?t=775982
Old Int's are the only ones I recall using that type of heater. I never did find a good replacement switch for one. IHC stopped stocking them about half a century ago!!!!!
39-48 Ford hot water heaters worked the same way and used a similar switch. Not always easy to find, but 42-48 seem to show up on eBay a little more often.
I saw that yesterday,,cool but my heater does have defrost outlets as you can see but they only work when the fan is reversed.
Ive never heard of reversing a fan motor to get defrost. All the heaters with a defroster that I've ever seen used an internal baffle to divert the moving air from the floor to the windshield. Usually it was controlled by a cable and could be adjusted to flow warm air in both directions at the same time. I'd like to see how this is hooked up. It doesn't make sense to me.
^^me too! Ill have to look up a 41 international heater. My brother has a scout, maybe he'll know something about it.
Here's an explanation of how the fan works and the 39 to 48 ford heaters are different as they had an internal baffle to select air to heat/defrost The heater is two speed, reverseing. There is a paddle fan near the core, and a squerll cage fan futher back. On the direct side, it pulls are from the rear and blows it thru the heater core, on indirect is draws air thru the core, and discharges it out the back of the heater. The defroster is fed off the squrrell cage (which blows the same.. from inside to outside of the cage, regardless of which direction the motor turns). When on indirect it gets the hottest air, as the paddle fan is drawing thru the core and dischargeing at the back where the defroster blower is, The de frost still works on "direct" but the air supplied is cooler, as it is the returning air from the cabin. Hopefully you marked how all the wires were connected before you dis assembled.
i have one of the international reversable heaters in one of my cars. i am not sure if the replacement 12 v motor will work. i used a resistor to drop the voltage to about 6 v for the origional motor. my son ( electro/ mech tech) figured out the wiring using a readily available toggle switch. mine is not variable speed, but that can be overcome with a varriable resistor or a hi/ low switch and additional resistor. if you want the wiring diag. or more info, pm me.
I have one that looks identical to the one with the doors that you used except it has outlets for defroster hoses. The motor has 4 wires instead of 2, the core is on one side of the fan and the defroster outlets on the other side. The fan would have to push for heat and pull for defrost. ======================================================= Whoops! Got to thinking and had to go look. The motor does reverse but there is a second housing with a squirrel cage fan for defrost which sounds like the setup jazz1 posted.
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