Toro Greensmaster 3120 - Page 213

TheGreensmaster3120hydraulicmanifoldusesseveralsolenoidactuated
cartridgevalveforsystemcontrol.Whenthesolenoidcoilisenergized,hydraulic
cartridgevalveshiftsandchangesthehydrauliccircuitow.T estingasolenoid
coilcanbedonewiththecoilinstalledonthehydrauliccartridgevalve.
TestingaSolenoidValveCoil
1.Parkthemachineonalevelsurfaceandlowerthecuttingunits.Makesure
theengineisoffandthekeyswitchisintheOFFposition.
2.Disconnectthewireharnesselectricalconnectorfromthesolenoidcoilthat
istobetested;refertoFigure94.
3.Two(2)differentsizesolenoidcoilsareusedonthemachine.Identifythecoil
resistancespecicationbymeasuringtheheightandthediameterofthecoil;
refertoFigure94andtheSolenoidValveCoilSpecications(page5–26).To
assistintroubleshooting,identicalsolenoidcoilscanbeexchanged.Ifthe
problemfollowstheexchangedcoil,aproblemwiththecoillikelyexists.
Note:Beforetakingthesmallresistancereadingswithadigitalmultimeter,
shortthemultimetertestleadstogether.Themultimeterdisplaysasmall
resistancevalue(usually0.5ohmsorless).Thisresistanceisbecauseofthe
internalresistanceofthemultimeterandtestleads.Subtractthisvaluefrom
themeasuredvalueofthecomponentthatyouaretesting.
4.Useamultimeter(ohmssetting)andmeasuretheresistancebetweenthe
solenoidvalvecoilterminals.
Note:Solenoidcoilresistanceshouldbemeasuredwiththesolenoidat
approximately20°C(68°F).Resistancemaybeslightlydifferentthanlisted
atdifferenttemperatures.Typically,afailedsolenoidcoilwilleitherbeshorted
(verylowornoresistance)oropen(inniteresistance)
5.Ifthesolenoidcoilresistanceisincorrect,replacethesolenoidcoil;referto
theCartridgeValves(page4–102).
6.Ifthesolenoidcoiltestscorrectlyandacircuitproblemstillexists,checkthe
wireharness;refertoAppendixA(pageA–1).
7.Aftertestingthecoils,connectthewireharnesselectricalconnectortothe
solenoidvalvecoil.
Greensmaster3120
Page5–27
ElectricalSystem:TestingtheElectricalComponents
17230SLRevC