Freezer fan makes a rattleing sound

The freezer fan makes a loud rattling sound when it stops running. I inspected the fan and found ice build up around the fan bracket opening. When the fan runs, it clears the ice build up, but when it stops the fan blade moves back slightly, hits the ice, and rattles until it stops running. Clearing the ice with a hair dryer stopped the problem for 2 months. Now it requires deicing almost daily. The fridge works well otherwise. Where should I start to troubleshoot further? Where is my defrost timer located, and can the timer be manually controlled?

Check the defrost timer and defrost heater. Sounds like it’s not defrosting

TNX JDMAN: Do you know where the timer is located on my fridge, and can it be manualy cycled?

Ben,

Check out this diagram. The defrost timer is #4. What you have is a standard Whirlpool defrost timer (your fridge was made by Whirlpool for Sears/Kenmore). Yes, you can manually cycle it for testing purposes. Just don’t turn the shaft too fast or you’ll need a new timer whether it was bad before or not.

Ben Tym
You should turn it clock wise only until it clicks and the compressor stops. Wait about 10 minutes and see if you hear the sizzling sound coming from the freezer. If you did then the problem is the defrost timer which has to be replaced.
If you did not then you have to remove the back panel form the freezer and check the defrost heater for continuity. If it checks OK then replace the defrost thermostat (bi metal) and it is going to solve the problem.
Good luck.
Gene.

TNX TEAM AND GENE: Did as you suggested, but came away with no solution to my problem: 1-Switched off breaker. 2-dismanteled freezer and waited until power was off 20 minutes. 3-Switched on power, advanced timer to defrost position, and observed defrost cycle: The heater got hot ,the frost melted in the drain hole, and the heater cooled down after all the frost melted; the timer advanced and started the compressor after 29 minutes. I then assembled freezer and put it back in to service. What do I check next??
PLEASE HELP

Ben Tym
Good job.
Now replace the defrost timer and the problem solved.
Gene.