How to Troubleshoot & Replace Whirlpool AP6007513 / WP3-81329 Defrost Timer

Parts ordered. Parts delivered. Parts installed. Verified operation. Freezer currently operating at -4 degrees F after 24 hrs. of operation. Issue corrected. Replace the two items ordered if this is your issue. For the cost not worth trouble shooting to verify specific part failure! 

New timer 

Turned the timer to confirm that the cycle was not operating correctly (short freezing cycle/ early defrost) replaced with a new defrost timer. 

Pulled evaporator panel out and verifyed that fan is running.then manually turned defrost timer and verifyed element is heating up.Then used a hair dryer to remove ice built up around the evaporator and ice in defrost water drain.Reinstalled evaporator panel and ran unit to verify that it will return to freezing temperature inside.Then ordered a new defrost timer.Installed it 2 days later and turned the timer manually to defrost position and made sure water started coming out of condensation drain as it can get plugged up with ice when there is a defrost problem.Timer automatically cycled out of defrost and the unit was back to running.Pushed the freezer back against the wall and called this job done.Thanks. On a side note the screw holes in the new timer are to small to use the original nut and bolts to remount it.A couple of small wood screws were used instead. 

Disconnected power first. Checked for continuity using a multimeter on the easy to get to items: 1. Heater showed almost zero ohms / continuity -> Good 2. Themostat showed continuity -> Good This meant that the defrost timer was probably bad. It was located behind the rear panel near the right rear corner. Changed out the timer and the problem was fixed. 

Reviewed parts diagrams and wiring diagram on back of freezer. Identified that it involved a mechanical timer to cycle through defrosting. Decided to replace that piece before going after the thermocouple or heating element (although those would be next). Ordered the defrost timer (which arrived just two days later). Simple replacement ... unscrewed two screws (1/4" nut driver), disconnected old timer, plugged in new timer and reinstalled screws. Actual repair, once the part was identified, ordered, and received, was less than five minutes. Ran freezer for two days to check function - it now holds below zero and doesn't build up ice. 

R & R (remove & replace). 2 screws out and back in. It gets no simpler. 

I read the stories on the website here and found the timer on the freezer and manually rotated the gear that should be turning normally by the timer's internal motor. At some point while I was rotating the timer (clockwise) manually, I heard a 'click', and at that point, the compressor turned off, the internal fan stopped running and the defroster heater turned on. I verified that the defroster was working by looking at the drip pan at the bottom of the freezer and I saw water dripping a few minutes after I had rotated the timer by hand. I bought a new timer from AppliancePartsPros.com (here) and got it in two days. Unplugged the AC cord of the freezer, removed two 1/4" hex screws with a nut driver, unplugged the four-prong plug on the timer and installed the new timer in five minutes The freezer is now frost-free again and getting down to -20 degrees! 

Bought a timer But it was not the correct one for the freezer so had to do it manually (turning the timer to the on position and waiting for it to defrost and then turning it back off. I was able to find the correct timer and now the problem is no more. Thanks Appliance Parts for having the part I needed. Quick shipping and no hassle shopping 

Appliance Pros suggested that a failed defrost timer might be the problem. We put the frozen food in the small kitchen freezer and ordered a new timer. With standard shipping we received it in two days. It took about 15 minutes to install and that includes hunting down a nut driver of the correct size. Four hours later and it was running at minus 5. Suggestion: We did not think about the amount of water resulting from the melting ice. Once the pan was full it was difficult to pull the freezer out from the wall without spilling water. (The timer is on the back.) If I were to do it over, I would pull the freezer out from the wall and unto a plastic sheet. Or better yet, haul it out to the patio while the ice is still ice. After the part arrives just tip the freezer forward a little and let the water spill out.