Solenoid Resistance: Do I have a faulty solenoid?

LESSON SUMMARY: This lesson is designed to assist the user in troubleshooting and isolating faulty solenoids.

Special Tools Needed: Digital Multimeter, Phillips Screwdriver, Flathead Screwdriver

CAUTION: THIS LESSON MAY INCLUDE INSTRUCTIONS TO TEST HAZARDOUS VOLTAGES (120V-240V) THAT CAN CAUSE SERIOUS INJURY OR DEATH. IT IS RECOMMENDED THAT A LICENSED ELECTRICIAN BE CONTRACTED TO PERFORM SUCH TESTS.

🛑 STOP: ALWAYS TURN OFF THE POWER TO THE SATELLITE BEFORE REMOVING ELECTRONIC COMPONENTS.


A shorted solenoid is a solenoid that has sustained damage, causing the solenoid to draw an excessive amount of current from the satellite’s power source. Shorted solenoids can cause components in the satellite to blow fuses and, at times, can cause damage to Power Transformers and/or Power Supply Assemblies. To test a solenoid, proceed with the following steps:

Start by powering off the satellite and isolating the solenoid(s).

To isolate the solenoid(s), unscrew the station wires from the connector in the satellite. Station wires are typically screwed into a screw terminal on a Switch & Surge Board, Terminal Board, TRIAC Board or Output Board.

Testing a solenoid can be done at the satellite using the station wires as a test point.

*Note: If you have two or more solenoids wired together and a short is found on the set, and if the wires are spliced together in the field, you will need to dig up the solenoids in order to disconnect and test them individually .

Using a digital multimeter set to the Ohm setting, measure the resistance of the solenoids.

*Note: If the multimeter has a range of settings to chose from, such as 200 Ohms, 2000 Ohms, or 20K Ohms, 200 Ohms should always be used. Do not use the audible continuity function on the multimeter for testing solenoids.

Proceed to place one probe of the multimeter on the Valve Common wire and place the other probe of the multimeter on the station wire.

See the graphic below for an acceptable resistance range based upon your individual configuration:

Digital multimeter on ohm setting
A good solenoid, reading 36.7 ohms

Solenoid Resistance Range (range may vary slightly):

Single Solenoid: 25-35 Ohms

Two Solenoids: 12-18 Ohms

Three Solenoids: 8-13 Ohms

Any low reading (0-5 ohms) generally indicates a shorted solenoid.


Test the remaining station wires by continuing to place one probe of the multimeter on the Valve Common wire and place the other probe of the multimeter on the next station wire.

If the digital multimeter displays a low reading of 0-5 Ohms, the solenoid is likely shorted. Shorted solenoids should be replaced immediately.


Lesson tags: hunter, toro, rain bird, rainbird, buckner, solenoid, solenoid testing, solenoid resistance, shorted solenoid, ohms, blown fuse, transformer, solenoid repair, solenoid exchange, solenoid replacement, boardtronics

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