Fan on my 544p wheel loader seems to work in forward but in reverse it runs max 600rpm. What would I be up against
Welcome to HEF george ! Machine serial number please.
You confirmed visually that the fan is changing direction? 600 rpm at idle or at fast idle?
Yes I can see the dust fly wen it reversed. 600 at all times. Engine over heats. I came as far as...wen I unplug the axle sensor the fan runs 800 at idle n 1800 at max rpm. But if I unplug the two sensors on the fan motor nothing happens.
While there is no published specification (yet) for the "P" model fan speed, maximum fan speed of an older wheel loader (K) is 1800 rpm. If you are reaching 1800 rpm, then I would think the fan speed is not the issue, but rather the control side. Unplugging the fan proportional control solenoid should also take it to maximum rpm. if you run it with the solenoid, or the axle sensor, unplugged, does it still overheat?
Wen the axle sensor is unplugged it doesn't over head. But can't figure out y it does run in high with proportional sensor unplugged. Cylinoid maybe done?
What codes are in the monitor, both active and stored? If the fan turns slow with a the all the temp sensors plugged in, and then speeds up with a temp sensor unplugged, the solenoid should be working fine. Did you unplug a solenoid or a speed sensor at the fan motor?
I unplugged both and fan doesn't speed up till I unplugged axle sensor. There is no code given.
Did you unplug the solenoid on top of the fan motor, or the one on the bottom? The one on top controls the fan speed, the one on the bottom reverses the fan direction.
I tried both but fan never defaulted to high speed.
Sounds like a sticking solenoid. The fan should have gone to full speed when the proportional control solenoid was unplugged.