05 9400i ISX Cooling Fan won't shut off

oh and no faults or codes

 

If the fan is engages just after key on then the ecm is getting a signal to leave the fan on. This could be from the override or a/c circuits, which may be where the problem is.

 

I think I found the fan clutch solenoid, up by the fuel water separator... a black and a red wire coming out of it, with 2 air lines and a pressure release...
is that it?

doesn't seem to be an air leak anywhere. tho difficult to tell really, with the engine running, don't hear anything when it's off.

tho like I said in the previous, when I shut off the motor, the fan WILL spin free for a second or two, then a burst of air from the release on the solenoid, and I can see the fan clutch engage and stop spinning...

I need to run tomorrow, will this mess things up even more if I run it all day in this situation?

I may just bring it in...
can't afford them guys tho, but can't afford to screw it up more either.

 

a/c pressure sensor maybe then?

 

Aslong as your fan is running you good to go! Go and make some money and then get it fixed.
10-1 they will replace a sensor.

 

i'll give it a try thanks lttle guy, did you get yours fixed?

 

A/C high pressure shows high pressure in the ECM when ever the circuit is open. So if you have a break in the wires somewhere the fan will be on all the time too. This can be tricky to find. Sometimes the best way to find is have a laptop hooked up to the engine with Cummins Insite running and monitor the A/C high pressure switch status that the ecm is seeing and just start wiggling the harness hoping to find the bad spot. Most breaks occur at sharp bends in the harness, or where it is tied too tight or immediately after the connector. Externally the insulation looks perfect. The wire has had just too many flex cycles back and forth, or too much tension and the copper strands inside are all broke. The wire will feel very floppy.

 

lil guy, have you narrowed it down yet?

and thanks HeavyD, how much is that program and how can I get it?
or can I even get it?