EngineCoolingFanCircuitProblems
Problem
PossibleCause
Coolingfanrunsonlyinforwarddirection(fan
doesnotruninreversedirection).
Fancontrolmanifoldsolenoidcartridgevalve
(S1)isfaulty.
Electricalproblemexiststhatpreventsfan
controlmanifoldsolenoidvalve(S1)operation
(seeChapter6:ElectricalSystem(page6–1)).
Coolingfandoesnotrotate.Coolingfanmotoriswornordamaged.
Lastgearpumpsectioniswornordamaged.
Coolingfanalwaysrotatesatslowspeed.Fancontrolmanifoldcartridgevalvesealsare
leaking.
Checkvalveincombinationmanifoldisnot
seating.
Fancontrolmanifoldproportionalreliefvalve
(PRV)isstuckopen.
Hydraulicfanmotoriswornordamaged.
Coolingfanalwaysrotatesatfastspeed.Fancontrolmanifoldproportionalreliefvalve
(PRV)isfaulty.
Electricalproblemsexiststhatpreventscorrect
operationofcombinationmanifoldproportional
reliefvalve(PRV)(seeChapter6:Electrical
System(page6–1)).
Groundsmaster
®
4500-D/4700-D
Page3–9Troubleshooting:
19245SLRevA