Fan stuck (Cummins isx)

Of course when you get the mechanic to see the ecm dump and has a chance to look at it, he can tell you to replace it or tell you what the issue is.

 

Check to see if there is a switch on the dash for "fan on" which you would use climbing a steep or long grade. This gives you manual control of the engine fan- it may be this switch is in the on position. The truck I'm driving right now is a 94 Volvo with ISX Cummins and the fan runs all the time too. It's annoying but being in the southwest (Arizona) it's kinda a mixed blessing.

 

My mixer had one of those. Didn't work though.

 

Is that not the utmost in frustration? Did you continue to try using it randomly during your piloting of said vehicle? That's what I do, unless I know for a fact that the its associated system has been removed.

 

Yea, but the auto worked just fine. They idle all day so the drum is always turning, and would use coolant.

 

Computer knows best.

 

I dunno about that lol.

 

I look forward to your findings.

 

A fan for a 850-871-2250-230 all work the same with the same inputs, engine speed, temp, throttle position, A/C command, Jakes, how you butt feels.... can be the worst to diagnose. But will always be a simple problem. If the only issue with you buying a unit is the fan buy it. You can diagnose a fan issue driving to Saskatchewan and you will find it as it's purely a operator noticeable item.
GL