2 wire blower motor

[tp tbird]

I have A/C on my 59 tbird and the blower motor has 2 wires(black ground and red hot wires) all the diagrams show 3 wire heater motors like the none A/C car on my other bird.I only have one speed on it (high)at the switch,is there not high and low speeds on the 2 wire motors with A/C ?Maybe I don't have the wiring right.

[jopizz]

You kind of answered your own question. For two speeds you need two hot wires (red and orange). You will only get one speed with a two wire motor.

John

[jopizz]

After doing some research it appears that there is a resistor on the red wire that allows it to change to low speed. I haven't seen one so I can't say exactly where it is. Yours may have gone bad if it only has high speed.

[tp tbird]

2 wire blower

I think cars with A/C have the 2 wire motor witch is bigger,I do have a smaller 3 wire motor I got sometime back with the same squirrel cage box for A/C cars,the cars without A/C have a different box and smaller motor.I don't see any resistor unless it is on the back of the heater A/C control .I do have a wires form what looks like a little coil in the bottom of the squirrel cage box that I thought was for just the A/C ,I don't have one hooked up(one orange and one red).

[Dakota Boy]

I've got a two-wire motor with a non-A/C blower housing.

I hooked it to the high-speed circuit, and for as much as I run the heater/defrost (hardly ever), that's fine for me.

There's a maintenance guy at work (we call him the "rabid spider-monkey" cuz he's a small guy, but full of **** 'n vinegar, and he can fix or build ANYTHING) who says he could make it into a two-speed motor with some cheap resistors. I'm sure he's right... I'm just not that motivated at this point.

[simplyconnected]

When T-bird started in '55, Ford used three-wire heater motors, and carried them over for years. For the '60 model, someone finally woke up and realized the motors don't need two separate field windings, they could be made cheaper, and they produce as many speeds as you want using resistors and switch settings. The more resistance the switch 'cuts out' the faster the motor goes. Eventually the motor gets full battery voltage for high speed.

Over time, and knowing a two-wire will work on ALL cars, the three wire motor became harder to find and much more costly.

Check out the difference in these two motors HL&B on the switches = Hi, Lo, Bat:

The resistor is close to the motor just under the duct. (Much later, someone got the brilliant idea of putting the resistor IN the duct. Hope this helps. - Dave

[tp tbird]

Thanks that was good to find out ,I didn't see anything on the two wire motor.I have 2 wires on the resistor on the bottom of the heater box,one that goes the the wiring harness and the other side is not connected to anything so if I connect the red from the resistor that is not connected and orange from the motor together I should have the low speed right as to the diagram it should work .

[tp tbird]

Two wire heater motor

Got the two wire heater motor connected to the resistor and now I have the low and high speed on the heater switch.Thanks for the information and help.

[simplyconnected]

Thanks for letting us know about your success, Thomas. AND, thanks for working on your own car. Now you're an experienced restorer for the next guy who finds a 2-wire motor, but thinks he needs a 3-wire. - Dave

[Jimz Bird]

GOOD Stuff!

Mine is 3 wire and works OK but if it should fail I could replace it with a 3 wire from one of the vendors for about $150.00 or a 2 wire for about $25.00. EASY decision there.

Resistors run about $10-20.00 and look like the below.

It would "seem" to be better to replace the OEM "heater coil" style with a modern resistor wired in line. Especially if going from 3 to 2 wire and have to add it anyhow.

So, what is the ohm rating of the OEM?

[tp tbird]

My 430 1959 convertible has been the biggest project that I have done to date ,and at my age most likely the last sad to say.
I just passed on a 56 tbird last month that was taken apart for restoration 30 years ago and in really good shape and right price,but I had no room for it.I use to have a 55 bird and 57 bird,some reason I always have a bird.I guess fords have been in my blood all my life except for a 53 merc and a 55 chevy I have had in the past years.Working on them was necessary for me as I could not afford to pay a shop to do it when I was younger.My first car was a 1941 ford business coupe I got it from the first owner,41 ford sedan,then a 1957 tbird from my uncle,he brought it new.From there I had a 1960 ford convertible sun liner,1935 ford coupe,1926 model t roadster pickup from the first owner,couple ford vans,and now I have 5 cars and a Harley

[simplyconnected]

Good research, Jim. This type of resistor goes inside a heating duct because it depends on air flow to cool it. Without air flow it would quickly burn open.Three speed fans use a resistor with two filiments and three connections. Most cars go to their grave wearing good fan resistors, so they should be an item that is cheap and readily available regardless of make or model (or you can pay dearly for a new one).

Notice the size of the wire! This is like coat hanger, built to pass ~5 to 6-amps. So the big electrical question is, what's the watt rating? A Radio Shack resistor won't disipate enough watts and will quickly burn out.

So, if Lo or Med speeds on your heater fan don't work, this is the culprit. They are easy to change and should be inexpensive enough to pick up a spare if you're passing a bone yard.

Here is a sketch of a three speed switch & resistor... - Dave

[Jimz Bird]

OK, makes sense to keep it cool.

So if I need to replace my 3 wire with a 2 wire then I should get this one and mount it in the heater duct?

thanks.

[simplyconnected]

Yes, Jim. Most modern car resistors are very easy to find, just follow the wires from the heater switch to the heater duct about 18 inches away (usually above the passenger's feet). Pull off three stabs and unscrew two screws and it's in your hand.

If the resistor has three connections and you only need two, you can use half of it if you want.

[430bird60]

Anyone know whether or not a 61 two wire blower motor will interchange with a 60 two wire motor? Thanks.
Ken