Appliances depend on timers to help them do your bidding. You'll find timers in the coffee maker, washer, dryer, dishwasher, and microwave, just to name a few. Knowing how timers work and how to fix them earns accolades in the Fix-It Club.
A timing mechanism controls current flow based on a mechanical or digital timing device similar to a clock. Timing mechanisms on small appliances usually turn the appliance on or off. Timers on major appliances—washing machine, dishwasher, dryer, frost-free refrigerator, or oven, for example—control the various cycles. Mechanical timers on large appliances consist of a shaft, gears, and a series of notched cams, one for each circuit or cycle. The timer is powered by a small timer motor. Digital timers are much simpler, using low-voltage electricity to control various functions such as turning on or off a device. While some timing mechanisms can be adjusted, those that are faulty should be replaced rather than repaired.
To test a timing mechanism:
- Unplug the appliance and access the timing mechanism.
- Set the multimeter to RX1 (resistance times 1) scale. Make a sketch of the timer wires for future reference, then disconnect all timer wires from their terminals. Make sure you'll be able to reconnect the wires exactly the same way when you're done.
- Touch or clip one probe of the meter to the common terminal. Touch the other probe to each cycle terminal in turn. Rotate the timer control knob as you work. The multimeter should read zero ohms meaning there's no resistance to the flow of electricity.
- If one or more circuits do not give these results, the timer is faulty and should be replaced.
- To replace a timer, disconnect its wires one at a time, connecting the corresponding wires of the new timer as you progress in order to avoid the chance of misconnection.
To test a timer motor:
- Unplug and disassemble the appliance enough to access the timer motor.
- Set the multimeter on the RX10 scale and connect the leads to the two motor wires. A good motor should give a relatively high reading (usually 2,000 to 3,000 ohms), but not infinite (meaning no electricity will flow through it).
- If the reading is infinity, replace the motor or the entire timer mechanism, as available.
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