WRF736sdam14 Whirlpool Refrigerator warm

[Salty74]

Hi,

Whirlpool french door bottom freezer. Top pantry freezing food for a couple of weeks then pantry is warm, 48 - 50 degrees. Cleaned condenser coils, worked well for a few days, temp is now back to 48 - 50. Disassembled the air duct from freezer to pantry & removed the air damper assembly. No ice blockage. Could feel air before I took it apart. Removed panel in front of evap coils, no heavy frost or ice. Had a little ice built up on back of panel. Entered self test mode. Test #1 & #2 fc & rc thermistors, all passed, displayed 01. 01=pass 02=fail 03=short. Test #3 evap fan & air damper 01=fan ON baffle OPEN, 02=fan ON baffle closed. This test cycles between 01 & 02, continuously running fan & damper motor. Started the test, baffle was moving and in the right position with the corresponding #'s. Cycled test 3-4 times. Exited service test mode then re entered sevice test, tested baffle again. This time test was flashing 02 at start of test & baffle wasn't moving but evap fan was on. Hooked multimeter to damper motor to monitor voltage. Started test and voltage would display 4-8 volts for a split second, fan would come on. Cycled test on & off several times with same results. Initiated test again, this time showing 120v evap fan on, damper motor moving. Did test a few more times 120v evap fan on, then reverted back to 4-8v evap fan on, damper not moving display stuck on 02. Does this sound like a possible intermittent control board issue or Power supply board issue? Any help in the right direction will be appreciated. Thanks

[Vance R]

1 hour ago, Salty74 said:

Does this sound like a possible intermittent control board issue or Power supply board issue?

Were you measuring at the damper motor or at the board? If at the damper move to the board to re-test. How are the temp in the freezer and refrig sections? Also check the air returns believe they behind the pantry drawer. Looks like the pantry drawer has a manual slide damper from the part exploded view.

BTW - the daig test for thermistors is very basic. Did you check resistances to see if thermistor are out of spec?

[Salty74]

I have all shelving and air duct removed from the freezer to the pantry so I can access the damper motor, it has been unplugged over night, as well with doors open. Tested voltage at the motor and at the board all while in service test mode, which should keep constant power to the damper motor until I exit the service test mode. I also did a resistence test on the thermisters which tested good. I have 2 boards on this unit. Power supply board & main control board. When I initiate the service test I can here a relay click which turns on the evaporator fan and should also turn on the damper motor. I've tested the damper motor feedback switch which tells the control board which position the baffle door is in. 01=open 02=closed on the display. Just a basic normally open switch. I have pressed the switch myself during the service test when the motor has no power, and the display for the door position doesn't change from open to close. I've also checked all door switches for proper operation.