How to Test a Refrigerator Door Switch

Do you ever wonder if the light inside your refrigerator ever really does turn off when you shut the door? Don't lie. You know you tried opening the door really fast and then very slowly to see if you can catch a glimpse of the light being off! In both cases you were probably disappointed because the light instantly turns on the second the door opens. This happens because the refrigerator has a compression door switch. When the door shuts, the switch's plunger is depressed, turning off the light. When it opens, the plunger pops out and the light turns on. But what do you do when you open the fridge only to find your eggs and milk in complete darkness?

Things You'll Need

• New appliance light bulb
• Screwdrivers
• Putty knife
• Multi-tester
• Needle-nose pliers

Instructions

1. Well, if the light in your fridge isn't working, the first thing you should do is ensure that you don't have any breakers tripped. Check the electric panel to see if any breakers are off or tripped. If everything is in good shape, then try replacing the bulb in your refrigerator.

2. Refrigerators typically do not use standard light bulbs. When you go to the store, look for appliance light bulbs. They are usually 40 watts, smaller and coated with a thin film. You want to avoid using a high wattage bulb because of the heat it produces. Appliance bulbs are specially made to be able to handle the cold environment in your refrigerator.

3. If you replaced the bulb and the light still doesn't work, then the door switch itself may be bad. To test the refrigerator's door switch, the first thing you should do is unplug the refrigerator. Or, if the fridge is too heavy for you to move to get to the outlet, just turn the circuit breaker that powers the fridge off.

4. 

   Open the refrigerator door and locate the door switch. It will look like a little post sticking out. If there are retaining screws, unscrew them and pull the switch out. If there are no retaining screws, then use the putty knife to pry the switch out of its slot. Be very careful when doing this so you don't break off the two cliplike wings that hold the door switch in place.

5. When you pull the switch out of its slot, there will be either two or four wires attached to it. Some door switches also control the refrigerator's evaporator fan in addition to the interior light. Draw a schematic of the wiring so you know exactly how to hook the wires back up to the switch after you have tested it.

6. Use your needle-nose pliers to pull the wire leads off of the door switch terminals. Do not pull them off from the wires--pull them off the terminals by the connector, or else you might pull the wires right out of the connectors! As you pull each connector off the door switch, take a look at both the connector and the terminal to see if you notice any corrosion. If a connector is corroded, replace it.

7. With all of the wires off, place the door switch on a level surface. Set your multi-tester to read ohms. This is sometimes the R1 or RX1 setting, depending on your tester. As you will see, without touching anything, the tester should be reading infinity. Touch one of the tester's probes to each of the door switch's terminals. The tester should now read zero.

8. While holding the probes in place, press the door switch plunger in (you may need a helper for this part). With the switch pushed in, the tester should read infinity once again.

   Switch out = Zero
   Switch in = Infinity

9. If your refrigerator's door switch does not deliver these readings, then you should replace it. Simply purchase a replacement, wire it up according to your schematic, turn the breaker back on or plug the fridge back in--and let there be light!

Tips & Warnings

• If you have to pry the door switch out with the putty knife, cover the tip of the knife with tape to prevent it from scratching the finish of your refrigerator.