Whirlpool auto dry question

Hi Sean, if you look at the wiring diagram, you can see that they wired the dryer in such a way that when either the operating or high limit thermostat open a circuit is completed to the timer motor through a power dropping resistor, this is because they use a 120 V timer motor same timer that they use on gas dryers, and the way the circuits wired the timer motor. If they didn’t use the power dropping resistor to 40 V would be supplied to the timer motor which would destroy it.

Some dryers have a 240 V timer motor that was pretty rare. In this type of circuit.

Whirlpool has been wiring their dryers this way since the early 80s and Speed Queen GE and probably everybody else does the same thing that’s what the little voltage dropping resistor is for on electric dryers ,gas dryers Don’t need the voltage dropping resistor, of course.

Wiring the dryers this way it’s less costly way of building them. It saves copper and makes it more reliable as you don’t have an extra contact in a thermostat that could cause a problem.


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Post# 1203970 4/22/2024 at 20:29 by Maytag85 (Sean A806)
Checkrate/Likes Watched a few videos of diagnosing thermostats and thermal fuses on a Whirlpool 29” dryer on YouTube. Anyways, I was wondering how the auto dry feature works since I don’t see a double throw switch thermostat, does it have a hidden wire somewhere I can’t see which goes up to the timer motor? Just wondering since that’s been on my mind since yesterday.

Post# 1203986 , Reply# 1 4/23/2024 at 10:57 by combo52 (50 Year Repair Tech Beltsville,Md)
Checkrate/Likes 1 *Thermostatic auto dry wiring* Hi Sean, if you look at the wiring diagram, you can see that they wired the dryer in such a way that when either the operating or high limit thermostat open a circuit is completed to the timer motor through a power dropping resistor, this is because they use a 120 V timer motor same timer that they use on gas dryers, and the way the circuits wired the timer motor. If they didn’t use the power dropping resistor to 40 V would be supplied to the timer motor which would destroy it. Some dryers have a 240 V timer motor that was pretty rare. In this type of circuit. Whirlpool has been wiring their dryers this way since the early 80s and Speed Queen GE and probably everybody else does the same thing that’s what the little voltage dropping resistor is for on electric dryers ,gas dryers Don’t need the voltage dropping resistor, of course. Wiring the dryers this way it’s less costly way of building them. It saves copper and makes it more reliable as you don’t have an extra contact in a thermostat that could cause a problem.

Post# 1204010 , Reply# 2 4/24/2024 at 00:00 by Maytag85 (Sean A806)
Checkrate/Likes Ahh. I was wondering about that for a little while, thank you for answering my question John. I thought about posting this in the Imperial forum index but since this pertains more to the newer Whirlpool 29” dryer with the auto dry, decided to post this here instead. Would it be possible to for example, to wire up my Maytag DE806 this way? Just wondering in case if the Supco LD120-15 double throw switch cycling thermostat decides to become NLA these days (not likely, but who knows) and want to see if it’s possibly to modify it in such a way where a regular cycling thermostat will work.

Post# 1204012 , Reply# 3 4/24/2024 at 08:25 by combo52 (50 Year Repair Tech Beltsville,Md)
Checkrate/Likes 1 Good morning Sean, I never thought about wiring up an older dryer to work this way, but I imagine it would work. As I mentioned, there’s not much advantage or disadvantage. It’s just a little bit less expensive to manufacture, and a little more reliable doing it this way.

Post# 1204047 , Reply# 4 4/24/2024 at 20:05 by Maytag85 (Sean A806)
Checkrate/Likes 2 It doesn’t hurt to try to experiment with doing different things, sometimes by doing something like that, you’ll learn something new and possibly discover another way to do things.