This guide details testing a potentiometer with a multimeter. Disconnect power, set the multimeter to measure resistance, and remove potentiometer wiring. Identify the three terminals, measure resistance between outer legs to match rated value, then test the wiper by rotating it and observing smooth resistance changes. Erratic readings suggest dirt or damage; clean with contact cleaner or replace if needed.
⚡⚠️ Safety First: Before you begin, disconnect the machine from its power source to avoid any risk of electric shock. ⚡
Step 1: Set Up Your Multimeter
- Turn your multimeter to measure resistance (Ω / ohms).
Step 2: Disconnect the Potentiometer
- Remove the potentiometer wiring from the circuit board.
- You can test at the end of the wiring harness or directly on the potentiometer.
Step 3: Identify the Terminals
- The potentiometer will have three terminals (legs):
- Two outer legs
- One center leg (called the wiper)
Step 4: Measure Total Resistance
- Place the probes on the two outer legs.
- The reading should match the potentiometer’s rated resistance (e.g., 5kΩ, 10kΩ, etc.).
Step 5: Test the Wiper
- Leave one probe on an outer leg and move the other to the center leg.
- Slowly rotate the potentiometer through its full range.
- The resistance should change smoothly as you turn the knob.
Step 6: Check for Issues
- If the reading jumps erratically, the potentiometer may be dirty or damaged.
Step 7: Repeat on the Other Side
- Keep the center probe in place and move the outer probe to the opposite outer leg.
- Repeat the test as in Step 5.
Step 8: Clean or Replace if Needed
- If readings are inconsistent or erratic, try cleaning the potentiometer with an appropriate contact cleaner.
- If problems persist, replacement may be necessary.