Toro Groundsmaster 4500-D Series - Page 335

SolenoidCoilTesting
1.Parkmachineonalevelsurface,lowercuttingdecks,stopengine,engage
parkingbrakeandremovekeyfromtheignitionswitch.
2.Locatehydraulicsolenoidvalvecoiltobetested(Figure214).
3.Disconnectwireharnessconnectorfromsolenoidvalvecoil.
Note:Priortotakingsmallresistancereadingswithadigitalmultimeter,short
themetertestleadstogether.Themeterwilldisplayasmallresistancevalue
(usually0.5ohmsorless).Thisresistanceisduetotheinternalresistance
ofthemeterandtestleads.Subtractthisvaluefromthemeasuredvalue
ofthecomponentyouaretesting.
COIL
DIAMETER
COIL
HEIGHT
g276030
Figure215
4.Usingamultimeter(ohmssetting),measureresistancebetweenthetwo(2)
connectorterminalsonthesolenoidvalvecoil.
Note:Solenoidcoilresistanceshouldbemeasuredwithsolenoidat
approximately20ºC(68ºF).Resistancemaybeslightlydifferentthanlisted
atdifferenttemperatures.Typically,afailedsolenoidcoilwilleitherbeshorted
(verylowornoresistance)oropen(inniteresistance).
A.Ifcoilissecuredtovalvewithanut,identifycoilbymeasuringthecoil
diameterandcoilheight(Figure215).Thecorrectresistanceforthe
solenoidcoilisidentiedinthetablebelow.
COILDIAMETERCOILHEIGHTCOILRESISTANCE
46.7mm(1.84in)49.9mm(1.96in)
7.1ohm
35.8mm(1.41in)36.3mm(1.43in)
8.8ohm
B.TheresistanceofthesolenoidvalvecoilintheHI/LOWrangecontrol
manifold(item4inFigure214)is7.1ohms.
5.Ifsolenoidcoilresistanceisincorrect,replacecoil(seeDeckControlManifold
Service(GM4500-D)(page5–134)).
6.Aftertestingiscompleted,connectwireharnessconnectortothesolenoid
valvecoil.
Groundsmaster
®
4500-D/4700-D
Page6–53
ElectricalSystem:ComponentTesting
19245SLRevA