Dryer was left in house we recently purchased. Now we know why, It didn’t work! The exhaust and much of the inside of the dryer was clogged with lint. I pulled the drum and after cleaning the lint have checked the control thermistor (45K ohms), the thermal limiter (short), high limit thermostat (short), and the heating element (short). The dryer runs but there is no heat. Can I check the motor switch by just using a line cord with spade lug connectors and applying 120 VAC to the motor and checking the switch for continuity? If the switch is bad, can I buy that switch from a motor repair shop? What about a schematic for the control board? What supplies the voltage for the coil for the heater relay? I am running out of things to check??? I have the dryer in my shop and I don’t have any way to plug it it to do live circuit test. I could wire it directly to a 220 breaker and use the breaker to apply power???
Any help appreciated!!!
Thanks
If the heating element is short then this part is bad. It should have some reasonable resistance.
You have to have 240 VAC to check how the dryer works.
It has to be done by a certified electrician.
Here is the Wiring diagram.
- The heating element assembly AP2107129
Gene.
Thanks for the quick reply. The heating element actual resistance is 11.3 ohms.
Is that reasonable? What about checking the motor switch? I’m planing on just using 110 volts on M4 & M5 and adding gnd, and checking resistance between M1 & M2?? Thanks Jeff
Jeff,
I did not get why do you want to check the motor if the dryer actually is not heating?
The very fist thing I would do is make sure there is 240 VAC at the dryer wall outlet. The motor needs just 120 VAC to run while the heater needs 240 VAC.
Gene.
The motor has a centrifugal switch between M1 & M2 that is in series with the heating element. I assume that if the motor is not turning, heat would cause a fire hazard. Terminals M4 & M5 are the 120 v connections to run the motor.
Thanks
Jeff
Thanks for the information. Here is what I did.
Wired dryer to 220 volt source and checked for heat. (None)
After checking voltages on schematic I jumpered the heater relay on the board.
HEAT
I then removed the board and the relay. The relay coil read 144 ohms which is correct. The board has several surface mount components so I decided that repair of anything but the relay was too much trouble. I re-soldered the relay and put the dryer back together. Now it works??? Could have been a cold solder joint on the board. Ran all of the test and everything seams to be working!!
Thanks again.
You are welcome. I’m glad you were able to diagnose and fix it. Good job!
Gene.
P.S. The motor centrifugal switch problem is very rare.