How many ohms should a fan relay have?
Problems In The Cooling Fan Circuit A good relay coil will typically read 40 to 80 ohms. If resistance is high, the coil may still be working but it is failing; or it may not work when electrical loads are high. If the coil has no resistance, it is open and has failed.
How do you test a fan relay with a multimeter?
Use a digital multimeter (DMM) to test the resistance between each pole of the relay and the corresponding NC and NO contacts for that pole. All NC contacts should read 0 ohms to the corresponding pole. All NO contacts should read infinite resistance to the corresponding pole. Energize the relay.
How to troubleshoot an electric cooling fan problem?
1.Has the Cooling Fan Actually Failed? 1 If the fan comes on when the AC is running at MAX, but doesn’t run when the engine is hot, check the temperature sensor… 2 If the fan fails to come on, first check for a fan blown fuse or triggered breaker. On older vehicle models, you may… More
What happens if one fan fails to come on?
If one or both fans fail to come on; the lack of additional cooling provided by the fan may cause poor A/C cooling performance. Also, it may cause the A/C compressor to overheat and fail. The engine may also run hot and overheat, too.
What happens when a cooling fan resistor fails?
The cooling fan resistor is meant to send power to the fans in steps, so that the fans may operate at different speeds. If any of the individual steps or switches fail, it will disable the cooling fans from operating on that speed setting. You may notice that the cooling fans only operate at one speed, when they used to operate on two or more. 3.
When do you turn on the cooling fan?
Once the coolant temperature sensor detects that the engine temperature has exceeded acceptable levels, the cooling fans will be activated to keep the engine cool. Many vehicles come equipped with cooling fans that operate on more than one speed setting.