How to Test a Limit Switch With a Multimeter

A limit switch is an electrical switch operated by the movement of a machine part or presence of an object. To test a limit switch with a multimeter you will need to set your multimeter to ohm mode and check for continuity. With the power off, disconnect the wires from the terminal screws on the limit switch.

Place one lead of your multimeter on each screw and observe that there is continuity when in the closed position (switch open) and no continuity when in open position (switch closed). If it does not show any reading then it is safe to assume that either there is something wrong with your wiring connection or that the switch has gone bad and needs replacement.

  • Set the multimeter to a resistance test setting, indicated as “Ohms” or Ω on the multimeter’s dial
  • This setting is typically identified by an omega symbol and can be found in the middle of most multimeters’ dials
  • Connect one lead from the meter to one terminal of the limit switch and then connect the other lead from the meter to other terminal of limit switch
  • Push down on either side of limit switch, this should cause an audible click when it activates and deactivates at each position
  • If no clicking sound occurs, check for any loose wiring connections or obstructions in operation mechanism causing switching difficulty before proceeding further with testing procedures
  • Take note of both readings displayed on your multimeter screen when activating and deactivating limit switches; if they are significantly different (above 10 ohms) ,this indicates that there is proper circuit continuity through contact points within device indicating proper functioning condition
How to Test a Limit Switch With a Multimeter


How Do You Know If a Limit Switch is Bad?

If you’re trying to diagnose a malfunctioning limit switch, it is important to understand how they work and what signs may indicate the switch has failed. Limit switches are electrical components that detect when an object has reached its maximum or minimum position. When the switch is triggered, a signal is sent which can be used as feedback for controlling other machinery.

A bad limit switch will typically cause problems in your system’s operation by either not triggering or triggering at inappropriate times, resulting in incorrect output signals from the machine. You might notice this misalignment if your machines start turning off or on unexpectedly, or perhaps if parts of your machine aren’t moving correctly anymore due to inaccurate input signals from the limit switches. To verify that a limit switch is bad, use a multimeter to measure resistance across its terminals and compare it with the manufacturer’s specified values.

If there is no continuity between these two points then there could be an issue with the switch itself such as corrosion on its contacts or damaged wiring within it. It also helps to rule out any other potential faults by checking all nearby connections before concluding that a particular component needs replacing.

How Do You Test a Limit Switch?

Testing a limit switch is an important part of ensuring that your machine or system is working properly and safely. A limit switch is a type of electrical switch used to control the movement of a device within its range. When the device reaches its limits, it triggers the limit switch, resulting in a change in current flow which can be detected by testers.

To test a limit switch, you’ll need either an ohmmeter (to measure resistance) or ammeter (to measure current). First, ensure that all power sources are disconnected from the circuit containing the limit switch before continuing with testing. Then use your meter to check for continuity between each terminal on both ends of the limit switch; if there’s no continuity then this indicates faulty wiring and/or connections in one or more parts of the circuit.

If there is continuity present then move onto checking for correct operation: activate and deactivate the device several times while observing changes in voltage at each terminal over time; any discrepancies here could indicate issues with either internal components or external connections related to them not being firmly seated into place. Finally, make sure to thoroughly inspect all wires for breaks and wear-and-tear prior to reattaching power sources as these may lead problems down line when running tests again!

What Should the Ohms Be on a Limit Switch?

The ohms on a limit switch should be set according to the manufacturer’s instructions. Generally, a limit switch should maintain an electrical resistance of between 10 and 50 ohms when closed. This ensures that current is being properly regulated and that the device will operate as intended.

If the resistance is too high or low, it could cause problems with operation, including false triggering of the switch or failure to trigger at all. Additionally, if you are replacing a limit switch, it’s important to use one with similar characteristics to ensure compatibility with your system. For example, if your old limit switch has a maximum operating voltage of 250VAC then you must select another model with this same rating in order for your new unit to function correctly.

What Voltage Would You Read Across the Limit Switch?

The voltage across a limit switch depends on the type of switch you are using, as well as its power supply. Generally, it can range from 3 VDC to 250 VAC. For example, an electromechanical limit switch usually has a rated voltage between 5 and 24 Volts DC while inductive switches often use up to 250 Volts AC.

Additionally, some types of switches may require special wiring or configurations such as ground fault circuit interrupters (GFCI) which could increase their rated voltage. Therefore, in order to determine what voltage would be read across the limit switch accurately, you should consult with the manufacturer’s specifications for that device or contact an experienced technician who can help you make sure your installation is safe and meets all applicable codes.

Checking a limit switch using your voltmeter

How to Test a High Limit Switch on a Dryer

Testing a high limit switch on a dryer is an easy process. To do this, disconnect the power to the dryer and locate the two wires coming from the high limit switch. Next, use a multimeter to measure resistance across these two terminals.

If there is no continuity or if it reads open, then replace the high limit switch. Otherwise, it is functioning properly and can be reattached to the dryer.

How Do I Know If My Limit Switch is Bad?

If your limit switch is not working properly, it may be time to replace it. Signs that a limit switch may need replacing include motor failure, unexpected stopping or starting of the machine, and strange noises coming from the motor. Additionally, if you notice that the equipment does not respond when you move a lever or pushbutton on the control panel, this could also be an indication that your limit switch is bad.

If any of these symptoms are present in your machine, then it’s best to get your limit switch checked out by a professional as soon as possible.

How to Test Limit Switch on Electric Furnace

Testing a limit switch on an electric furnace is an important step in maintaining the efficiency and safety of your heating system. To begin, shut off all power to the furnace, and then remove the cover panel. Once you have access to the wires connected to the limit switch, use a multimeter set to ohms mode to test for continuity between each terminal.

If there is no continuity or resistance reading when testing each terminal, it indicates that the limit switch needs replacing.

Should a Limit Switch Have Continuity

Yes, a limit switch should have continuity. This means that there should be an uninterrupted electrical path from one side of the switch to the other when it is activated. If there is not continuity, then the switch will not work properly and may cause problems with your system or device.

If you are ever in doubt about whether or not your limit switch has continuity, you can use a multimeter to check and make sure.


In conclusion, testing a limit switch with a multimeter is not only easy to do but can save you time and money when troubleshooting an issue. By following the steps outlined in this blog post, you should be able to quickly and accurately determine if your limit switch is faulty or not. If it turns out that it is faulty, then replacing it should take care of the problem.

With some experience and practice, using a multimeter to test a limit switch will become second nature.

Leave a Comment

Your email address will not be published. Required fields are marked *

Scroll to Top