I have a Trane Xe-60 furnace about 19 years old. During summer months, with thermostat set to deliver air, the outside condenser runs, but furnace blower does not. I can move thermostat lever from auto to on and fan motor blows. Same problem with heat, no heat on auto. I sometimes have to go to furnace, remove lower door, and push the switch that door presses against to start fan motor. All help appreciated. Syan

If the unit is running in cold weather than there is ice building up on the coils located outside. This is normal in that the unit is running in heat pump mode heating inside and cooling outside, After the unit detects the ice build up it briefly reverses the cycle heating the outside coils melting(defrosting) the ice which you observe as water on the pad.

The video gives you an example of the defrost cycle!
2012 Trane XL15i Heat Pump Defrost Cycle Steam Show

Due to the many different questions I see about Air Conditioning, I am including this overview to help us better understand each other for trouble shooting. A basic air conditioning system has a Thermostat, Air Handler or Furnace Fan and a Condensing unit. In a split system, the condensing unit (Condenser) is separate from the furnace and usually in the back yard. When working properly, it blows hot air. It connects to the cooling part of the system by 2 copper lines. One large line and 1 small line. The part that cools the house is the "Evaporator" and is usually on top of the furnace inside the square metal box (Plenum). When the Air Conditioner is running, the large copper line should be cold and the smaller line should be warm. Common signs of low refrigerant are that both lines are the same temperature and/or frost or ice has built up on the large line at the condenser. The thermostat will normally display room temperature on till it is touched to change the setting. It could have a "Span" setting as well as times and temperatures. The operating "span" of MOST residential thermostats is 40 to 90 degrees. That means you can set it as low as 40 degrees and no higher than 90 degrees. It probably has a fan switch also. When in the "ON" position, the fan will run constantly, 24 / 7, but the condenser will still cycle on and off as needed to keep the house at set point. If you have a suggestion to include in this paragraph, please let me know.

I think I have it covered above. Let me know if you need something more specific. Thank you. Roger

Did the 2 fans have the same rpm. If there is not enough airflow through the outside unit the compressor will shutdown on high discharge pressure. Also make sure the fan blades are positioned right if there is a shroud for them. Did the other motor have a capacitor with it or did you use the 1 from the smaller motor. Sometimes the motor data plate will tell you what size capacitor you need. Let me know what you find.

The fan runs continously because your condensor is not kicking on and removing the heat. The thermostat needs to come under the set temp. to kick off the fan. If your compressor doesn't run and the fan on the outside unit does run, your compressor has an issue. If nothing runs outside, then your transformer on the inside unit(air handler) has an issue. This could also be a control relay on the condenser or the air handler.

Bad thermostat, improper wiring or bad circuit board in furnace. Turn off the disconnect outside.

you can switch the thermostat to "emergency heat" which will turn the outdoor section off and the thermostat will control the electric heat elements in the air handler if it has them.

high limit is open try tapping on it gently

If the manufacture says it is the IFC then you should have the IFC checked by the company who installed it if it is under warranty still

the problem sounds like a defective capacitor its located on the condensing unit outside, also a contactor that is used can be defective also.