Cooling fan cycling…Help!

[jerammo]

Hello,

My Mazda2 1.3 DE biofuel (Dutch version modified to LPG), cooling fan cycles on and off every few seconds, even if the engine is cold.

The thermostat works fine, the coolant temp switch was changed without effect. According my research the on/off signal for the fan comes from the ECU.

What could cause this false output?

 

[anthonbuck]

What's your coolant temperature when it comes on?

 

[jerammo]

The fan cycles on and of every few seconds even with a cold engine and the blue coolant indicator is still on. My mazda doesn't have a temperature dial , only a blue cold Light or a red too Hot Light.
I don't have real high temperature issues.

 

[anthonbuck]

The fan cycles on and of every few seconds even with a cold engine and the blue coolant indicator is still on. My mazda doesn't have a temperature dial , only a blue cold Light or a red too Hot Light.
I don't have real high temperature issues.

You need to verify the temperature your ECM is getting from the temperature sensor then you can know if it's a short circuit in the fuse box or wiring or bad temperature sensor or ECM or relay.