Kenmore 110.62802101 Dryer - auto moisture function not working

[jmm]

I posted a few days ago that the auto moisture sensor function was not working on our dryer. The heating element is functioning and the dryer will shut off using the manual timer. I replaced the moisture sensor but that didnt fix the problem. THRAMICH suggested that I check for a grounded heating element, and then verify the moisture sensing circuit using the thermostats and wiring. Using my multimeter I verified that the heating element was not grounded and that the thermostat, hi-limit thermostat, and thermal fuse were all good. I then checked the internal bias thermostat. There was continuity across the outer contacts (red and red/white wires) but not across the inner contacts (purple wires). I'm unsure if this means this part is bad and if so, would that explain why the dryer is heating but the moisture sensor does not work. Thanks for your help.

[Vance R]

1 hour ago, jmm said:

There was continuity across the outer contacts (red and red/white wires) but not across the inner contacts (purple wires).

The purple wire are for a bias heater to make the thermostat open at a lower temperature, the spec is 5.6k to 8.4k ohms.

1 hour ago, jmm said:

I replaced the moisture sensor

Was this the metal contacts or the module?

[jmm]

I replaced the entire module.

[Vance R]

55 minutes ago, jmm said:

I replaced the entire module.

Ok now the fun starts.

2 moisture sensor strips - 1 is attached to chassis ground, 1 is attached to a yellow wire with a red trace (y-r) that wire goes to a terminal on the moisture sensor module. Need to verify first strip is grounded and the second strip is NOT grounded and the wire is good all the way to the module.

At the module - green wire with yellow trace (g-y) is attached to the chassis ground.  During operation there should be 120 vac at terminal with orange wire with white trace (o-w). The neutral is on the tan wire with white trace (t-w) and is through the motor centrifical switch - only completes the circuit with motor running. The white wire with black trace (w-b) is attached to the timer motor for neutral. The way timed dry works is the timer just bypass the module control to neutral.

[jmm]

Its working! I verified that the first strip on the moisture sensor was grounded but the second one was grounded as well. Traced the wire back and noticed that the circuit board it plugs into was pulled slightly out of its socket. Plugged it back in, tested it with a damp dishrag, and its working. Thanks for your help!

[16345Ed]

22 minutes ago, jmm said:

Its working! I verified that the first strip on the moisture sensor was grounded but the second one was grounded as well. Traced the wire back and noticed that the circuit board it plugs into was pulled slightly out of its socket. Plugged it back in, tested it with a damp dishrag, and its working. Thanks for your help!

Nice job!

 

Good call again Vance. 

[Vance R]

@jmm Your welcome, glad you found the problem.