2007 peterbilt fan will not shut off

[hct5]

i have full air pressure going to the solenoid but only a little pressure going out due to the low voltage from the ecm. i can put 12 volts to the solenoid with a power prob and the fan spins freely take it off and plug it back in and the fan locks up. insite says that the fan demand is 0. everything looks good on insite it is set to on/off fan type and 0v to turn on. it is stock.