Electrical - 1961 Imperial blower motor wiring?

[jim1941]

Will be changing the non-working blower motor for my a/c and heater. Replacement is coming from a Mopar parts supplier. New motor shows only two wires; one red and one black. Existing original motor has three; the green and brown (plug) and a separate ground wire.  Question is, I don't understand how to wire the new motor to the plug.  And what about ground?  The motor has three speeds on the dash. I've included a photo of the shop manual wiring diagram if that helps. 

Jim

[Gary56]

I need some advice of how to rebuild the Gages of a 1939 graham paige?

[Frank DuVal]

Jim, sounds like the wrong motor. The original motor has two windings, HIGH and LOW according to the schematic.

 

Now, most other heater motors I am familiar with  internally ground the winding, so there is just one wire or terminal to hook up. Maybe the new motor does this, so the two wires are HIGH and LOW, and there is no external ground wire. Call your supplier. The red and black colors would make one think there is just one winding, and the black wire is to be grounded to chassis.

 

Do you have the new motor already? And an Ohmmeter? Check for continuity from the red wire to case and the black wire to case. If there is continuity, maybe it is a two winding motor with internal ground connection.

 

Gary, good question. I have not had mine out, so I cannot answer. Please start a new thread with Graham in the title to ask the question, maybe someone will know Grahams gauges. The guy in North Carolina has had lots of Sharknoses apart. I will search for his name in the magazines of GOCI. Joining GOCI would be a GREAT first step.👍

[jim1941]

Thanks Frank.  I'll have to wait until the motor arrives, but am now thinking it won't work like original with different speeds. I do have a continuity tester and that will be an easy test to start with.  

[61polara]

If this blower motor will fit in every respect except that it is a single speed motor you can add a resistor to the low speed circuit wire to give you two speeds.  You can join the two power feed wires after the resistor to a single wire to attach to the new style motor.  With single speed blower motors, direct 12v power input gives you the highest blower speed.  To lower the blower speed, the power is directed through a voltage resistor or multiple resistors to further reduce the speed.  Many cars with manual blower speed controls used this setup from the factory.  Here is an example:

Blower Motor Resistor ECH BR85 | Buy Online - NAPA Auto Parts (napaonline.com)

 

Just search NAPA for "blower motor resistor".  This one just happens to be for 1989 Dodge Dakota.  You should look for one with an outside case though.