My Whirlpool Dryer (Mod # LER6634DW0) will not heat. I have performed the suggested continuity checks (always removing one connection from each device when it was tested) with the following results. Note: all other functions seem to operate normally except that for the last few months the "start button" doesn't have to be pushed to start the machine. We have just been using the rotary timer to activate & turn off the machine.

1. 240V shows up on terminal strip where power cord enters machine
2. With machine running, there is no voltage to terminals of heater coil.
3. Heater coil measures 10 Ohms
4. Thermostat (High limit, 250deg; 3390291) shows continuity (0 Ohms)
5. Thermal cutoff (hi limit; 3399848) shows continuity (0 Ohms)
6. Thermal Fuse (3392519) shows continuity (0 Ohms)
7. Thermostat, internal bias (3387134) shows continuity between "far terminals" but NO CONTINUITY between opposite terminals that are close together. I tried tying these two together to see what would happen ... the heater still did not activate.

There was a lot of lint buildup near the blower wheel when I took off the lint chute assembly, but that is now 100% clean and the blower wheel seems to be working fine.

Any ideas?

BTW, I do not have a circuit diagram for this unit. Is there one online?

Thanks for any help/advice you can offer.

Thanks for the input and the circuit diagram. I only shorted the leads for a 15 sec test. The heater never activated so I disconnected them and put them back where they came from.

I will check the start switch, but even if the contacts are always closed (meaning "start" is always commanded) wouldn't that allow the heater to operate? I'm asking because, while I'd like the start switch to work, that is not my #1 problem ... #1 is getting the heater to activate.

I will check the timer switch as you recommend and will report back.

Thanks again.

Yeah, if it requires a new motor ... I'm buying a new dryer. Not worth putting $100+ in a 16 year old dryer when a new dryer is $389 (+/-).

I'll bet its your timer part no. AP2976173

With the timer set to time dry, you should have continuity from Line 1 to the red wire on the back of the timer. (timer switch 2)

If not, a contact is probably burnt off inside. Sometimes I just take them loose and shake them. If you here something rattling around inside the timer, its toast.

[COLOR="DarkRed"]Left input lead (Black wire - L1?): 240 volts
Middle input lead: 120 volts
Right input lead (Red wire - L2?): 0 volts[/COLOR]
The above looks OK to me.

[COLOR="DarkRed"]I'm not an electrician[/COLOR]
FYI: here is what your power in is:
the middle connector: is Neutral/ground (0 volts)
the left and right: are power L1 and L2 (120 volts).
When referenced to Neutral they are 120 volts but they are 180 degrees out of phase. So when one is at 120 volts positive, the other is at 120 volts negative and therefore if you measure L1 to L2 you get 240 volts. This is what runs your heating coil.
Wattage is voltage times current (amps) so if we can double the voltage we can half the current to get the same wattage out. With half the current we can use a smaller wire size which is cheaper so it all comes down to economics all the way back to the power companies transformer.

[COLOR="DarkRed"]so I was reluctant to use my ohm meter, but its a cheapie so I put it on x1K and measured the resistance from the timer's red lead to the right input lead (the one showing 0V above) and it showed continuity (0 Ohms).[/COLOR]
If they both had a red wire on them then I think that would have been timer switch 2 and it is closed as it should be whenthe timer is in a dry mode. I cannot confirm this as the timer in the parts breakdown does not show the back of it.

[COLOR="DarkRed"]BTW, one last fact (not previously mentioned): The two sides of the heater coil show 0 voltage between them BUT both do show 120V to ground.[/COLOR]
This would be normal. If timer switch 2 is closed then you will see the L1 voltage all along the heater circuit all the way to the right hand side of the heater. You see 0 volts across it because the centrifugal switch 1M/2M is open.
[COLOR="DarkRed"]
Also BTW (but probably unimportant), the Start switch is now operating normally. All this fussing around must have "fixed" it![/COLOR]
Cannot explain this sounds like it is messing with you.

[COLOR="DarkRed"]If all of this cements a diagnosis, I would appreciate your conclusion. I promise not to draw this out any further![/COLOR]
Do not worry about drawing this out I volunteer here in order to help people as long as you are willing to put in the time I do not mind continuing. I help you, you help someone else and the world is a better place.

My conclusion is that the centrifugal switch is not closing. You can confirm this by unplugging the unit, removing the wires (they should be the heavier gauge red wires) from the motor's switch and shorting them together. Tape them so they cannot short to anything else and also that they will not get caught up in any thing when the unit starts up. Then plug it in and give it a try. If you now have heat you know that the switch or it's activating mechanism is toast and unfortunately the unit needs a new motor.