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The furnace control board has no activity on it's LEDs. I have no command of heat, cool, or fan. I started with resetting the breaker, then tried a new digital thermostat. I also tried attaching the thermostat to the furnace with a new piece of 24" wire to try and eliminate a short. I checked power to the door switch and checked fuse and all seem good. I have the same power input level from door switch to circuit board to transformer line in. I have zero power coming out of the transformer load. I have tried a new circuit board which bought me to a new model 83M00. This replacement board has a yellow/green wire that is extra, there was nothing in the install directions regarding this wire. I have also tried a new transformer. What seemed like an easy, logical fix has not turned out to be so. Any suggestions would be appreciated, I don't think our space heater is going to keep up with the arctic chill headed our way. Thanks.
 

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The furnace control board has no activity on it's LEDs. I have no command of heat, cool, or fan. I started with resetting the breaker, then tried a new digital thermostat. I also tried attaching the thermostat to the furnace with a new piece of 24" wire to try and eliminate a short. I checked power to the door switch and checked fuse and all seem good. I have the same power input level from door switch to circuit board to transformer line in. I have zero power coming out of the transformer load. I have tried a new circuit board which bought me to a new model 83M00. This replacement board has a yellow/green wire that is extra, there was nothing in the install directions regarding this wire. I have also tried a new transformer. What seemed like an easy, logical fix has not turned out to be so. Any suggestions would be appreciated, I don't think our space heater is going to keep up with the arctic chill headed our way. Thanks.
Do you posses and know how to use a VOM meter?
 

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well, i need to know how much voltage is going INTO the transformer, If you don't have enough going in you will get nothing out.Put the meter on VAC and measure the voltage between L1 and L2.Remember to have the door switch depressed or taped or whatever........
 

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there u go.......if you measured correctly , you don't have any high voltage. Possibly a bad door switch, bad ssu , blown fuse or tripped breaker. I just want to make sure that you measured correctly......you have a black and a red lead on your meter, and its set to VAC and you put one lead on L1 and the other on L2 and got.058 ?
 

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I placed the black electrode on ground and red to L1 and L2 individually. When I placed black on L1 & red on L2 the meter read. .000. Individually each read (.580v)
I have a yellow/green to chassis ground already I guess I could put the other down as well.
 

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The black breaker is connected to transformer load and is receiving no power. It seems power is stopping at transformer. Maybe I connected this wrong? It seems like that is not possible because the tabs are of different sizes.
 

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You should have 120 volts instead of.058
Try L1 on one meter lead and the other meter lead to ground. If you get 120V that way the the neutral wire going to the furnace is broken.
 

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The black breaker is connected to transformer load and is receiving no power. It seems power is stopping at transformer. Maybe I connected this wrong? It seems like that is not possible because the tabs are of different sizes.
You have no power going to the transformer.


please check the power like i told you to do in a previous post......its important that you do exactly as i tell you so we are not missing something
"......you have a black and a red lead on your meter, and its set to VAC and you put one lead on L1 and the other on L2 "
do not check it to ground.
 

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Okay, I have to ask. Is this is a 120 volt gas furnace or a 240 volt electric air handler? No, I haven't checked the manual. :)

What are we looking for across L1 and L2 and why not to ground? Tells wonderful tales, to ground.
 

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Okay, I have to ask. Is this is a 120 volt gas furnace or a 240 volt electric air handler? No, I haven't checked the manual. :)

What are we looking for across L1 and L2 and why not to ground? Tells wonderful tales, to ground.
Its gas, and reading from L1 to L2 will give you your potential voltage, reading to ground will vary and can be deceiving.
 
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Checked three electric air handlers today, pole to pole and individual leg to ground, one to make sure 15 kilowatts divided my 241 volts (total of each leg to ground) equated to 62.2 amps. Two legs of 120 on 4 awg wire (which is rated to 75 amps) each leg to a 70 amp Square D double pole breaker that was tripping in heating mode.

Guss what the problem was? Yup, they need an electrician, bad breaker.
 

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Thank you for being patient with this greenhorn. I'll check again. I borrowed this multimeter and not sure how to set it. It is a radio shack auto-range digital. I have it set to volts. If I place this in a regular outlet I get (.300v) I'm running down to check again
 

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Thank you for being patient with this greenhorn. I'll check again. I borrowed this multimeter and not sure how to set it. It is a radio shack auto-range digital. I have it set to volts. If I place this in a regular outlet I get (.300v) I'm running down to check again
you should see 120 volts give or take a few......makes me wonder if you have it on VDC instead of VAC ?
 

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Thank you for being patient with this greenhorn. I'll check again. I borrowed this multimeter and not sure how to set it. It is a radio shack auto-range digital. I have it set to volts. If I place this in a regular outlet I get (.300v) I'm running down to check again
I think you have it on milivolts. It should be on Volts Alternating Current, VAC.
 
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