KW w/ ISX engine fan issues

What are the exhaust, oil, and coolant temps reading?

 

I had a 2007 KW in the shop for a fan running continuously.
It had a temp sensor for the fan in the power steering reservoir.
There was a broken wire going to that sensor.

 

Also ck. the eng. temp. sensor on the eng. that now has more wires leading every/where and you will have to ck. all of them to see if there is a raw place in a wire where they have been rubbing together or on a clamp that had rubber on them when new but after a few years the rubber goes away and rubs all the wires that are held raw and short out and make things diff. to find the exact place that wiring harness is worn thru, I have found replacing the Eng. temp. sensor fixes some trucks with fans running all the time, the intake, A/C, eng. temp. and about 4 other sensors will turn on fan ?

 

Yea there's like 8 or 9 sensors that will do the fan.

On mine is was the low side AC switch that would go bad.

The AC has 3 all by itself lol.

Unplug them all one at a time and put a jumper wire in the lead.

All those sensors are normally closed.

When you put the jumper in one, and the fan de-clutches, you have your culprit.

 

hook up a manifold to the AC system and check for high pressures. Had a sticking TXV cause that a while back. Intermittently spikes in pressure causing the fan switch to turn the fan on. It is usually on for a minute before it turns off. but if it keeps spiking in pressure it will keep turning it on before the minute passes.