1946-1949 Under Seat Heater wiring

[Upnorth]

Hello from Canada  I recently purchased a 47 4 door and I am in the process of sorting out a few issues. I managed to free up and get the under seat heaters working again with a jumper wire to the drivers side terminal under the car

I am having trouble finding out where the wire plugs in under the dash.  I am hoping there is a fuse some where I can check

Any suggestions or pointing me in the right direction would be a great help.

Thank you

[Joe Jensen]

If your '47 under seat heater is similar to my '49 then you will have a plug (see red arrow in picture).  That is where the under seat heaters plugs in.  There is a fuse off of the ignition switch, you can see half the fuse holder hanging off the workbench in the picture.  This fuse works for the defrost motor and under seat motor.  If your defrost works your issue could be the switch that turns on the under seat motor.

The switch is the round piece with wires going in/put.

Good luck!
Joe

[toybox]

As state above the defroster and the heater share a fuse . On my 46 coup the heater switch was/is bad . I believe this to be a common problem as when these cars got older . Debris found it's way down to the fans and added just enough resistance  to overload the switch to a point of scorching the contacts to a crisp. I ended up with a after market switch out of sight under the dash. I hope you find a better outcome then I did.  Tim

[Upnorth]

Hey thank you for the information It helps alot

Sorry does the heater switch run off the valve or is it on the dash with the defroster (defrost works fine)

[toybox]

The under seat heaters run off the rheostat on the control valve which is supplied power from the heater switch on the dash if my memory serves me right. Tim

[Upnorth]

Tim thank you for the update I guess my real issue is. I had no idea  how the seat heaters come on.

I think I have it now I ran the car today inside my shop it warmed up nicely still no heat I am guessing unless the car is outside and cold inside the heaters will not start

cheers Al Sinclair

[toybox]

 Al,                                                                                                               
         In my 46 if they are switched on they come on ( the fans ) immediately. Just no heat until the engine warms up.                                                                                      Tim

[Jeff Hansen]

All,

Attached are pages from the 1942 Accessory Data Book which explain how the Automatic Heating System operates. The system and description are identical for 1946 and 1947.

HTH,
Jeff

[Upnorth]

Jeff thanks kindly for the information it appears I should relax and wait. The information is excellent

 I did find  a small capillary tube attached to the block that appears to go to the heating valve ( I am guessing this is the on control) and another one from the valve that stops under the dash by the steering column (Temp control ?)

Does anybody have a guess on what controls the fan speed

many thanks to all for the  help

Cheers Al

[toybox]

The rheostat controls the fan speed the capillary tube controls the temp if the valve still works. I had to get mine rebuilt. Just an FYI, my wife has a cousin out in Colorado that is giving us a 1947 (series 62 I believe) four door sedan 100% complete . This car has been sitting in a barn yard since 1973 in the very dry south east Colorado. It will be for parts only and I'm using the manifolds and fog/driving lights. If you need anything after that give me a shout. 
                  Tim

[Upnorth]

Tim thank you for your input and offer of parts it is greatly appreciated .

I will do a walk around my car shortly and see if there are any bits missing or in need of replacement.

There are not a lot of spare parts here in Canada to say the least.

Take Care cheers Al