Need to totally re-wire my air handler.wire harness melted.found that the blwer motor is bad,cap.blown,and transformer.i need to now how to delete the bunt out harness.the unit is a coleman evcon down flow

Looking at the wall thermostat, you will see the fan switch that has two settings: fan auto, fan on.
You will need to place the fan switch in the fan on position for testing purposes.
This will make the indoor fan run continuosly, and never cycle off.
In the fan auto position, the fan will turn off when the thermostat temperature setting has been satisfied.
Remove the air handler access panel.
Is the air handler fan operating?
If the fan isn't working see if you can listen closely if it is humming, or can touch the motor to see if it is hot.
If it is humming and has a bad capacitor, you can tell this without having an electrical tester by spinning the fan wheel by hand.
Be very careful... making sure your hand won't get cut by the fan wheel spinning when it starts up.
If the fan spins and picks up full speed, replace the defective fan capacitor.
It is the shiny silver metallic cylindrical object with electrical wires attached to it.
Make sure you write down where those wires attach and turn the power off before removal as they carry 240 volts to the fan motor.
If you find that the fan wheel doesn't turn freely when you try to spin it by hand, the bearings have seized and you will need to find another fan motor of the same size, shaft length , speed , and horsepower to replace the defective motor.
Keep in mind that a humming sound in the air handler COULD be from the transformer instead of the fan motor.
The transformer is a black cube shaped device with electrical wires attached to it.
If the 24 volt transformer goes bad, your thermostat will not function and nothing will come on.

I think that most likely shorted out your low voltage transformer. Transformer is most likely located in air handler. You may find a blown fuse for transformer or bad transformer.

This should cover it.

Check for power to the air handler.
If you have power there,check power on the low voltage side of the transformer in the air handler.
No low voltage out of the transformer is will need replacing.
There may also be a 3 to 5 amp fuse on the air handler control board that is blown.
Any auto motive fuse of the same size will replace it.

Hi,
Usually that is because of a blown fuse in the air handler or fuenace which ever you have or the transformer that supplies the 24v to the thermostat, also in the air handler or furnace, has gone bad...
Check to see if you have 24v at the transformer and then flow it from there...

heatman101

Hi,
maybe a blown fuse if it has one... if not then you blew the transformer...
Check on the circuit board in the furnace or air handler for a fuse...
if there isn't one... then you will need to replace the 24v transformer... they blow very easily...

heatman101

Either you have blown the low voltage fuse located inside the air handler (if there is one) or you have blown the transformer feeding the low voltage control wiring.

If the transformer is blown due to no fuse installed, I would recommend installing a low voltage 3A fuse in line with the red terminal coming off the transformer. This will protect the transformer in the future.

It's a 24v transformer. Your indoor unit houses the transformer for the outdoor unit. The outdoor has a low voltage (24v) supply running to it to push in the contactor for the outdoor unit to run. If your air handler inside has no power then it will kill your LOW VOLTAGE power to the outdoor unit. You will still have the high voltage power to the outdoor unit. You may have a fuse on the switch for your air handler blown if there is one. On the disconnect switch mounted to your air handler, you will have a door to open and a fuse in there. If not, check your main breaker at the panel. If you don't know what a transformer looks like, you may want to have someone familiar with electrical of HVAC help you. To check the transformer for power, you first need power to your air handler, which you don't have. I would say that is not your problem. I would assume your air conditioner is not running outside, correct? Your problem is the power (HIGH VOLTAGE) to your air handler. Loose wires, blown fuse, tripped breaker etc...

Stopped up drain line caused float switch to trip. Blow out drain line. Blown fuse in Air Handler. Bad transformer. You have a 3 ton on a four ton air handler. You need to lower fan speed to low dor better effeciency. Could have bad Tstat butchances are control voltage problem.

I am not familiar with this air handler, but I haven't found too many with fuses. You just blow the transformer... but if you found a place that says there is a fuse, maybe there is.
If you can use a volt meter, check the voltage between the red and blue wire in the thermostat. It should be 24 volts AC. If it is there, your problem is something else... Some might suggest you use a short jumper wire from the red to the green and see if the fan comes on to check your 24 volts if you don't have a meter, but I would never suggest that...
If you determine that the 24 volts is not there then you should find that transformer in the air handler and follow the leads out and see if they lead to the fuse, if it exists. You might consider that the transformer is bad if you can't find a fuse. If able, check the primary for your supply voltage, 115 or 230 volts AC, and the secondary, 24 volts AC.
If your lucky, someone that is familiar with this model will answer with all the locations, etc...
Always be careful when working with electricity. If you decide to get into the air handler to troubleshoot your transformer, turn off the breaker while exploring and only turn it back on when you are ready to make voltage measurements and are confident that you know what you are doing.