Dryer repair DIY gone wrong... partly...
Just registered to relate my recent dryer repair story and ask for a bit of advice since it went a bit off the rails.
TL;DR (i.e. the short version): Timer runs any time the dryer is plugged in, and will even rotate through the stop position into the next cycle. Heat will be applied to the coils, even without turning the start knob, and without the drum spinning!
We have a basic GE dryer (one start knob, one setting/timer knob). Recently it started making noises. I watched a number of youtube videos detailing how to open it and remove various components. After unplugging the dryer, I pulled the top and front panels off and removed the drum. The sound was pretty high-frequency, so I was fairly confident that it was a motor issue, and not a problem with the slow-rotating drum / bearings.
All the same, I verified the rear bearing was ok, the front bearing pads were ok, the coils were giving proper resistance, the thermostats and safeties were all closed circuit at room temperature, and the resistance of the control inlet and timer-to-coil resistor. All checked out.
At that point I decided to buy a replacement motor. Ended up getting a motor assembly (not just the motor) including a new fan etc. Got that installed and replaced all the wires* (incorrectly). Put the drum and belt back in. Plugging the machine back in and moving the timer to "air fluff" immediately caused my house main to trip (as well as the dryer circuit). I believe I saw a flash of light from somewhere in the cabinet on the right side, but I can't find any scorch mark yet.
After that I unplugged again, removed the drum and examined my wiring. Turns out I mistook the brown wire for the purple (they're very close colour in my dryer - I had even taken a photo to make sure this wouldn't happen, but I still botched it, clearly).. I had plugged brown into the motor, and purple into the idler spring switch. Flipped those back around and rechecked all connections.. replaced drum and belt, and then plugged in the dryer again.
Soon as I did that I heard the timer motor running... however it shouldn't have been. It was in one of the Stop regions on the dial. I moved it to air fluff, and then hit the start switch.. drum started up normally, sounds were gone, so I figured I was basically done.. I moved the timer dial around to Stop, but nothing happened.. drum kept turning. Tried each of the other stop regions.. again kept turning. I opened the door, and the drum stopped.. however, when I moved the timer dial again to various positions it actually started up the coils! I could see the glow in the back of the cabinet and feel the heat. Moving to air fluff turned the coils off.
Final test was: Unplug the machine. Open the door. Set timer to air fluff. Plug machine in. Watch timer.
The timer started up, moved through to the end of the timed cycle, passed the stop point, and entered the +Dry cycle, lighting up the coils... argh!
Anyone have any idea what could be wrong at this stage? I suspected the Start switch, but with timer set to "air fluff" I tried: Start knob, drum spinning, open door, close door... the drum did not start up spinning again.
I rechecked all the thermostat continuities.. resistor values.. coil resistance.. all seems ok. I'm very pleased the sound is gone with the motor replacement, but obviously worried about the fact that my dryer is running without being "started".
Help much appreciated.. Thanks!
Most likely fused the timer contacts closed when you had it wired incorrectly. Impossibly to say for sure without a wiring diagram.
Hi there, thanks for your reply.
I don't have a timer schematic yet, but will look for one. This is the dryer schematic for my particular unit: http://www.freeinfosociety.com/elect...ew.php?id=1583
Update: Thanks to Protocol's suggestion about timer contacts, I pulled the timer and opened the casing. Found that indeed two of the contacts (leaf springs) had welded together. Scorch marks were visible on and around that pair.
They were well and truly joined; could not be pried apart. A hacksaw was able to separate the leaves, and I was able to smooth the surface out again.
After some effort I was able to get the case back together by aligning the cams and gear spindle with the case.
Ran the dryer again and found that it did stop in the Stop positions, however the coil appears to still energize without the blower motor running (i.e without hitting the Start switch).
This is leading me to believe it's related to the "motor switch" on the schematic. Bit worried about this one.. is it inside the motor itself??
I assume that when you say coil you mean element.
Motor switch will most likely be a centrifugal sw on the motor itself. You can double check by testing ohms or continuity between m1 and m2. Alternatively, you can test live by 1 probe on M2 and other probe on neutral or ground and see if you get 120V constantly, or if you only get 120V when the unit turns on.
It could also still be the control timer. I persoanlly would have just replaced the timer instead of taking it apart.
Edit: Forgot to add. The contacts should be open when the motor is not spinning. Contacts should close when motor reaches correct speed.
Yep, I meant the element.
Will check continuity on M1 - M2. Thanks for the suggestion.
I don't think I'll test live unless I have to. After proving I don't know how to hook things up right I think I'll avoid playing with 240V :eek:
And yes, I considered getting a new timer... but it's Sunday (my local parts store is closed), and I'm impatient. :)
Just following up to let you know that the problem is resolved...
Either as a result of my bad wiring, or the motor assembly I bought being a bad unit, the motor centrifugal switch was not functioning. The M1 - M2 connections were bridged even when the motor was stationary. They should only be connected when rotating, so that the element can only activate when the motor is blowing air through the unit for cooling.
I was able to salvage the switch unit from the old motor and replace the one on the new motor with it. The switch unit is actually integral in a single housing with all the motor pins (a black housing at the back of the motor).
Interestingly, the schematic shows a connection between the M1-M2 switch and the M5-M6 switch, however they are actually independent switches, housed within the same unit.. separate lever for each one. The M5-M6 switch was working fine on the new unit.
I suspect the switch may have been bad when purchased, as my mis-wiring blew the circuit while the motor was stationary, meaning those contacts should have been open when current flowed and should not have fused like the ones in the timer. I may crack the case of the switch to see if it was a short or just a bad build or something else.
Anyway, dryer functions beautifully now.. quiet as new, and I feel like I know my dryer inside out now! :thumbup: Can't wait until my washer breaks so I can crack it open. Already been there with the furnace.
Thanks for your help Protocol.
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