Fan not coming on at 210F for Cummins engine

I have a 2006 volvo. Fan is not cutting on at 210F when climbing an uphil like before. I disconnected the fan clutch solenoid and the fan comes on. Could it be solenoid? Thanks in advance.

 

Did you get this issue repaired yet?

 

No sir. I replaced solenoid, high pressure switch for Ac. Fan works as usual. Its just not coming on at 210F. Also i loose air pressurewhen i climb hills

 

If the fan works as usual, when does it engage? Does it engage at lower engine temps or when the A/C is running?

The fan solenoid is controlled by the ECM and the ECM receives inputs from other sensors like the A/C High Pressure Switch and the Engine Coolant Temp Sensor.

When you are climbing a hill how much air pressure do you lose?

Do you hear the air compressor engage/disengage like normal or is it running all the time?

Does the air system fill to the preset PSI and then does the governor shut the pump off and spit the water out?

 

The fan works when am stopped and idling as it should. It will go off when i start driving. I was messing with the solenoid to see if the clutch is working. When i disconnect power from solenoid the fan kicks in. When i connect back the solenoid the fan goes off. So am ruling out solenoid. I replaced Ac high pressure switch today. Still not fixing the issue. Am leaning now on the coolant temperature sensor. Everything is working. Only that the fan is not kicking in at 210F. Am not loosing much air. Where could the coolant temp seonsor be on the 2006 cummins isx?

 

On the ISX the coolant temp sensor is located on the thermostat housing.

 

You think it could be the culprit?

 

Yes, absolutely. The ECM uses the coolant temp sensor as a direct input for fan operation.

What I would do before replacing the coolant temp sensor would be to remove the sensor when the engine is cold and measure the resistance in the sensor and then measure a new one at your local parts store and compare.

The sensor is cheap enough anyways so replacement will not break the bank!

 

Thank you for getting back with me. Will update on the results. Stay safe

 

I went to locate the sensor and this is what i found. Thanks buddy.