IHC heater fan question

I noticed that the heater fan switch in my 1949 KBS5 has a center "off" position, with two speed settings to each side. One side is marked "direct" and the other is "indirect". Could anyone explain this? Does it simply reverse the fan direction? I have not yet tried to operate it, as I have it disassembled for cleaning.
Thank you in advance.
oldbike99

I noticed that the heater fan switch in my 1949 KBS5 has a center "off" position, with two speed settings to each side. One side is marked "direct" and the other is "indirect". Could anyone explain this? Does it simply reverse the fan direction? I have not yet tried to operate it, as I have it disassembled for cleaning.
Thank you in advance.
oldbike99

Careful of your switch! Very Hard to find.
Answer your Question. one way blew into the cab, the other way blew for defrost.
That is what I understand.

lloyd

I would not be surprised if the same switch was used by other manufacturers and if so,,would the switch have the same effect on a 12V motor,,reversing the fan on demand.

No, it is fairly unique in how it is wired. So far a 12 volt motor wired such as that 6volt one has not been found.
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.

Cornbinder89,
Thank you for the detailed explanation. I had noticed that they used separate blades for the core and the defrost and suspected that the motor was reversible, but your explanation as to "why" is what I really needed. Thanks to everyone.
Oldbike99

P.S. For once, I waited to disassemble it until I better understood it!

Has anyone found a replacement switch. I have been told 39 - 48 ford worked similar as far as the switch reversing the fan but I have not been able to find one. I have a 12 volt motor on my heater running a off the shelf variable speed switch,,,lots of heat but no defrost..

[quote="robertkb48"]first who ever told you the 39 up 48 ford heater fan switch works the same for revereseing the heater fan motor has no idea what there talking about.

nor do they have any idea how said heater motor works are what the heater even looks like making a statement that the heater fan switch on said years of fords and the international heater refered to in this post are simular.

with this said the 39 clear up into like 52 fords used a heater that looks pactly the same as the double barn door ihc heater.

but the 39 up to like 52 ford heater is a 3 door heater and not 2 like the ihc double barn door.

yet it shares the same style heater fan and heater assembly minus the front/heater cover and heater as the heater tubes are in a differant locastion on the ford verses the ihc.

next i belive you will find both the ford and ihc heater were made buy the same after market company/supplier as heaters were an added cost item and not factory.

even though you could order a heater and it would be installed at the factory because it was a factory offered item/option.

contuineing on even though the international double barn door heater and the 39 up to 52 ford heater share the same basic heater there 2 total differant heater in reality because theu function differantly.

the differance being is the internantional heater has no baffle whats so ever.

instead of a baffle they made the motor run in reverse buy using a specail polairty switch to resevse the motor in place of an inturnal baffle so you had a defroster and a heater.

but with out with the specail polarity motor reverseing switch the double barn door heater would be either a heater are a defrost depending on how you wire the motor and not both a heater and a defroster.

yet on the ford they used a built in inturnal baffle that was installed in the heater body/assembly part were the ducting tubes contact to the heater.

than the baffles were controled 2 differant ways.

reason why is because they made 2 differant vershion of the ford heater even though they both have the same baffle system and at first look they look identical.

in all reality they are identical yet there differant due to the fact the way the baffle system is operated/controled

onto the the first style which they refered to as the deluxe heater as the baffle system in it is controled buy inturnual rod system.

this style has a liilte knob on the front/face of the heater and you pull the knob which in turn controls a rod that is hooked to the bafle that allows the bafle to be opened for heat and closed for defrost.

the other style which was the standard model had a dash mounted manual cable that inturn was hooked to the bafle to control the heat/defrost.

how ever on the ihc heater you had to use the specail unick to international and international only and turn the switch 1 way for heat and the other for defrost as the double barn door ihc heater did not and does not have a inturnal bafle.

i know all this not only because i have owned and parted 6 42 to 47 ford pickup but because i was going to put a 39 up to like 52 ford heater in my kb1 because the ford heater has the intrual bafle.

as well as the ford heater uses a common readily avalble heater motor unlike the ihc double barn door heater which require a again specail and unick to ihc and ihc only which is obsolete and no longer avalble any were unless you get lucky and find a nos one yet highly unlikely.

also the ihc heater requires a special unick 1 of a kind polarity resevreseing switch that only ihc and ihc used and it to is osbsolete and no longer avalble are made buy any one.

this said i only knew of the standard style heater for the fords and only found out about the deluex heater looking for a standard heater.

another thing nice about the ford heater ververses the ihc is that the ford use a common every day standard heater switch.

how ever some people have change the switch and instead put in a non stock rehosat type switch so they can control the seep of the heater motor due to the fact the orgional motor was just a single speed motor and with the rehosat switch you can speed up are slow down the heater motor yet it will only go the speed it was made to and no faster even though you have a rehosat switch instead of the normal stock 1 postion 1 speed switch.

in closeing and all said/exsplained the ford heater in no way shape are forum used nor does it use the unick one of a kind polarity reverseing switch that is found/used only in the ihc trucks with the ihc double barn door heater that was the factory installed heater option for the k/kb and some ls.

lastly i am not trying dis on any one are put any one down.

instead all i have done and tried to do is exsplain/set thing straight so every one knows and understands that the 39 up to 52 ford heater even though they look practicaly identical to the double barn door ihc heater and should fit with modifaction to the firewall for mounting purposes and pluming of the heater core that there now were the same nor do they work/function/operate exactly indentical to the ihc double barn door as is being pretraded.
hope this helps and does not confuse any one.


robertkb48

windigo69 - I went through my heater a year or so ago and if I remember right there's nothing really unique about the motor itself, but I've never seen another switch quite like that one that can both reverse and adjust the speed. But you could try a two switch combination. You could continue using your present switch for speed adjustment and add a toggle reverse polarity switch to get your defrost. Basically then you have the same function as the original switch, but with 2 switches.

Another thing you could try is using a 5 position speaker selection switch from Radio Shack and then just work the wiring out to match the need. I think I have a wiring diagram for the switch here somewhere if you need it.

hi to add a couple more things.
first the motor its self is ineed a unick motor to the international double barn door heater and it is not just a plain common motor.

second there is a way you can wire in a double pull double throw toggle switch and use a modern motor and switch and do away with the stock ihc 1 of a kind unick motor and swtich used only in the internationals with the double barn door heater.

i know about the double pull double trow toggle switch due to the fact it was posted many many many years ago on the very very first adtion of oldihc as well as i was thinking about doing this same thing on my kb1.

yet i desided againgst doing it for sevral reason and just went to a more modern brand new vintage air heater unit.

further more using the double pull double throw toggle switch will create allot of heat and it is a potacial fire hazzard.

so when i was considerdering doing it i was going to us the rely and had bought 2 relays from napa which are long gone now because i never did it.

lastly all i remember is that the double pull double trow toggle switch are relays have to be wired in a certain way/series to make it work and i do not recall/remember how it was done as it has bin to long ago as well as i never did it.

hope this helps robertkb48

nd simple fact it causes alott of heat and possable fire hazzard.
yet to prevent the heat issuse

Well I don't need a fire,,already set the wife's vacuum cleaner on fire. I think I will just get an oscillating fan I can attach to header panel until I come across a heater that has a manual lever or something to take care of defrosting issues. The heater will be old,cheap and efficient!
Thanks to all who responded.