UPDATED**Nordyne/ No heat in auto-only in vent mode??

[Robert]

Hi,

Not having 240vac could mean several things, but not a bad transformer.


Yellow and Orange wires.


Follow them to nearest connection point to see if there is 240vac there for them, 120vac to each one.


Thanks,
Robert

[Ereed2]

Ok Robert, I have some news! Got my trusty meter out and checked....I do have 240vac onthe orange and yellow wires at the molex connector. I hope its not the motor as I just had it replaced a lil over a year ago?! Thanks again!

[Robert]

Was that while in the heat-auto mode ?

Are there any more connection points between the molex connector and the motor for those two wires ?

Does the motor leads end of the molex connector plug look ok inside ?


Thanks,
Robert

[Ereed2]

Yes Robert, that is in "Heat" "Auto" mode, there are no more conections from there, from there it goes straight into the blower motor, from what I can tell the insides of the molex plug look fine, any ideas?

[Robert]

Hi,

Look at the side of the motor and see if it shows the blower speeds with the wire colors.

IF the yellow is either low or medium low and orange is one of the line wires, then with 240vac at the plug, it should be getting to motor.


If so, then the motor would be bad.


Thanks,
Robert

[Ereed2]

Robert, the wiring diagram shows the yellow wire to be motor low and the orange is going to the circuit breaker, so I have a bad motor?? If so it didn't last long, I just replaced this not 2 years ago, which one is it on the order page here, are there any cheaper alternatives? Thanks for all your help!

[Robert]

Set t-stat to call for heat and then with 240vac going to motor, reach in and spin blower wheel hard in correct rotational direction and see if motor starts running and runs complete cycle.



Thanks,
Robert

[Ereed2]

Hello Robert, did as you said, called for heat, had my meter leads in the yellow and orange wires going to the motor and gave the fan wheel a spin and got nothing.? If the motor is bad, is there just one speed in it( the one that I need fo heat) that is bad cause it works fine in "Cool" mode and "Vent", just not in heat? Thanks Robert, you've certainly been a huge help!

[Robert]

What are the wire colors coming from your motor ?



Thanks,
Robert

[Ereed2]

Hello Robert,

Colors from motor are:

Red-
Black-
Yellow-
Orange-
Blue-

[Robert]

Hi,

Black = High = Cooling and Fan On Continuous
Blue = Med. High = nothing
Yellow = Med. Low = Heating
Red = Low = nothing
Orange = LINE = half of the 240vac (120vac/1 leg)


Try connecting the wire from board that is connected to yellow, try connecting it to the red wire.


THEN, if it works, take a reading at furnace return air grille and at nearest supply register to furnace for temps.

Low may be too slow, whereas Med. High would possibly be too fast.


Thanks,
Robert

[Ereed2]

So just run the yellow wire to the red wire? Red doesn't go to anything though.? Far as I know there is no board. Didn't understand about taking the readings at air grille? Thanks!

[Robert]

Hi,

Yep, no board, was just one of those circuit board days. Remove yellow motor wire from molex plug and remove red wire also, then place red wire where yellow wire was.


Get a pocket thermometer and place it in furnace return air grille (louvered door) to get return air temp.

Then do same at the closest floor or ceiling register, whichever you have.



Thanks,
Robert

[Ereed2]

Will do Robert! Will it hurt anything to run the motor like this...if it runs? Thanks!

[Robert]

Hi,

Shouldn't hurt anything, you're just lowering heat speed from med. low to low. Most furnaces use the low speed for heating.


Check the return and supply temps to get temp rise and compare to data sticker or nameplate temp rise specs.



Thanks,
Robert