Pre-war (up to 1942) 1939 LaSalle 5019 Heater

[39LaSalleDriver]

As we enter the fall season, I have decided to reinstall the heater unit I took out of my car when I began restoration last winter. I have taken it all apart, cleaned it up, and repainted it as necessary. As all of the wiring was a mess when I got the car, I had no faith in how it was all hooked up electrically.

Using the heater diagram I found here, I took the liberty of updating it for clarity. It appears to me that there should be four wires coming from the motor rather than the two that I have. When taking it all apart, I found a tag dated post August 1983 stuck into the birdcage blower which indicated to me it had been rebuilt at some point. Perhaps the extra wires were removed then.

Does anyone have any suggestions on how I should rewire the switch with the equipment I have? Thanks

[Barry M Wheeler #2189]

Jon, I do not have the info needed that you ask for. But I was remembering the winter of 1958/59 when I was driving my (first car) 1941 6127 equipped with the basic heater like yours. Be warned, it will drive you out as far as heating goes. It did the job it was supposed to.

[Steve Passmore]

My guess is the heater has been fitted with a modern single action motor and is wired just POS & NEG.    All the extra wires were for the reverse speed plus the 2 speeds and the rheostats in the switch.  Can't see how the two could ever be connected.

[J. Gomez]

Jon,

If the coil shown on your diagram is part of the motor itself most likely the motor is what is called a DC shunt motor. The shunt or coil in your picture is the field and it is in parallel with the motor armature this is all inside. So if the original one had 4 wires coming out of the motor housing those were the two “F” and two “A” wires.

The DC shunt motor can have the field and armature wired separately or both together, the advantage with these type or DC motors is that they can be wire for forward or reverse rotation be reversing the polarity and they can be relative easier to control their speed with smaller wire resistors.

If yours got changed to the normal DC (series type stator winding type) motor these can’t be reversed in rotation by reversing the polarity, they also required a bit larger resistors to control the speed.

HTH

[39LaSalleDriver]

Will address some of the other points later when I'm not on my phone,  and I hate typing on my phone.  I don't know if this information will help or not,  but I did jump the motor wires to make sure it works. I discovered that if I reversed the wires the motor would run the opposite direction. So maybe it will reverse for heater and defrost,  but have no variable speed?

[J. Gomez]

Will address some of the other points later when I'm not on my phone,  and I hate typing on my phone.  I don't know if this information will help or not,  but I did jump the motor wires to make sure it works. I discovered that if I reversed the wires the motor would run the opposite direction. So maybe it will reverse for heater and defrost,  but have no variable speed?

If you can reverse the rotation by reversing the polarity you motor maybe the permanent magnet type, those you can reverse rotation by reversing polarity.

If the switch provides the forward and reverse under the original motor,  it may be a bit complicated to make it work with the new motor since the switch moves the same polarity over to a different terminal/wire up to the original motor.

You can rig a set of relays so they can be wire at the switch to reverse the polarity up to the new motor, one will make the motor go forward and the other would make it go reverse.   

Good luck…!

[Tom Boehm]

Hello Jon, I had the same problem when I restored my heater. I obtained the correct motor from Bob Hoffman on this forum. I also got a  reproduction heater wiring harness from YnZ. It goes between the switch and the heater motor. It is four color correct cloth covered wires in a woven cover. The switch and the heater all work the way it is supposed to.

[39LaSalleDriver]

Jon, I do not have the info needed that you ask for. But I was remembering the winter of 1958/59 when I was driving my (first car) 1941 6127 equipped with the basic heater like yours. Be warned, it will drive you out as far as heating goes. It did the job it was supposed to.

That seems to be the general consensus on these heaters, but I hate the cold and will be willing to give it a go! 

If you can reverse the rotation by reversing the polarity you motor maybe the permanent magnet type, those you can reverse rotation by reversing polarity.

If the switch provides the forward and reverse under the original motor,  it may be a bit complicated to make it work with the new motor since the switch moves the same polarity over to a different terminal/wire up to the original motor.

You can rig a set of relays so they can be wire at the switch to reverse the polarity up to the new motor, one will make the motor go forward and the other would make it go reverse.   

Good luck…!

I'm no electrical engineer, but I think I understand what you mean...maybe.  I will experiment a bit with the switch to see what happens. I'm pretty sure that with the parts I have I can make it blow for either the heat or defrost, but I'm suspecting that it will be a single speed/off type of affair. I can tell that somebody, somewhere along the line had it hooked up to at least be able to do that. I'll try to report back what I come up with.

[DaveZ]

If there are only two wires coming out of the motor it has been changed. The heater/def combo had four wires. one for each brush field and arm. The switch had 5 positions. Off center. Turning one direction was for heat, high and low the other was for defroster, high and low. It works by reversing the polarity which changes the direction of the motor. You can set it up with just the heat. You will have to hook the wires up so motor spins correct to turn fan blade. The hardest part to find for these things I have found is the 5 way switch. If you have the switch keep it and look for a motor:-) Somewhere I have the motor number written down. Redmond I think was the manufacturer.