Recently, my dryer stopped working. It would start fine, run for a few minutes, and then stop. Once stopped, it can't be started up right away. Pushing start will sound the buzzer, but nothing else happens. Changing the position of the dial to different cycles will not change this behavior. After it has had a chance to rest for a while, the process can be repeated.
It will do this in any of the three cycles, including the fluff part of the knit cycle (no heat).
While searching online for help, I found
the wiring diagram linked from another post in this forum. With its help, I've tested various parts, both when 'ready' (ready to start) and when 'overworked' (refuses to start).
I've check the resistance across the control thermostat, high limit thermostat, and the thermal limiter. The reading are the same when 'ready' and when 'overworked', with resistants at about 0.5 ohms, except for the part of the control thermostat that reads 28k ohms.
I've been able to get it in an 'overworked' state, cut the power, pull the clips, get the reading, reassemble, re-power and confirm that it is still in it's 'overworked' state. This assures me that it didn't become 'ready' during my tests.
While running, everything seems to be working normally. Heat cycles on and off normally. I've stripped out the drum and door (wiring the door switch closed) and have been able to watch it run. Blower blows. Coil cycles between glowing and not. It didn't get 'overworked' while in this state, but I may not have run it open long enough to test.
I think my tests have eliminated the thermostats and I'm inclined to suspect the motor. I've tested the connections of the motor when 'ready', with the results being open connections, with the exception of the M4 to M5 (as per the wiring diagram) being closed. This makes sense to me given my limited understanding of the diagram.
However, when I tried to test it in an 'overworked' state, I got the same results and, upon reassembly, it was back to it's 'ready' state. This makes the results of the test suspect, as I could have been testing a motor that was again 'ready'. Either way, I think the results would be the same as long as the motor is not actually running (which would make testing rather hard).
I haven't tested the timer yet. My main suspect is still the motor and I'd like to pursue further testing on it.
So, my questions would be:
Any thoughts on what could be wrong?
How can I test if the motor is the cause of failure?
Other than the timer, which I will eventually get to if I can't pin the problem on the motor, is there anything else I could be testing?
And, for anyone who understand the wiring diagram, what is the function of the connection between the high limit thermostat and connection R of the timer? I have a general understanding of most of the paths shown. I just don't understand that one.
Anyway, thanks for any help anyone could provide. I welcome any corrections or critiques. I have a rather basic understanding of these things and I'm trying to learn what I can to be able to deal with such problems as they arise.