Toro Groundsmaster 4300-D - Page 294

Themainpowerandglowrelayareattachedtoaframebracketunderthehood
nexttothehydraulicpumpdriveshaft(Figure176).
TestingtheRelayswith4Terminals
1.Parkthemachineonalevelsurface,lowerthecuttingdecks,shutoffthe
engine,settheparkingbrake,andremovethekeyfromthekeyswitch.
2.Toensurethatthemachineoperationdoesnotoccurunexpectedly,
disconnectthenegative(-)cablefromthebatteryandthendisconnectthe
positive(+)cablefromthebattery;refertoServicingtheBattery(page5–94).
3.Locatetherelaythatistobetested.
4.Disconnectthewireharnesselectricalconnectorfromtherelay.Removethe
relayfromthemountingbracketfortesting.
Note:Beforetakingthesmallresistancereadingswithadigitalmultimeter,
shortthemultimetertestleadstogether.Themeterdisplaysasmall
resistancevalue(usually0.5ohmsorless).Thisresistanceisbecauseofthe
internalresistanceofthemultimeterandtestleads.Subtractthisvaluefrom
themeasuredvalueofthecomponentthatyouaretesting.
5.Checkthecoilresistancebetweentheterminals85and86withamultimeter
(ohmssetting).Theresistancemustbeapproximately72ohms(Figure177).
6.Connectthemultimeter(ohmssetting)leadstotherelayterminals30and
87.Thengroundterminal85andapply+12VDCtoterminal86.Therelay
shouldmakeandbreakthecontinuitybetweentheterminals30and87as
+12VDCissetandremovedfromterminal86(Figure177).
7.Disconnectthevoltageandleadsfromtherelayterminals.
8.Replacetherelayiftestingdeterminesthattherelayisdamaged.
9.Iftherelaytestingiscorrectandacircuitproblemstillexists,checkthe
platformwireharness;refertotheElectricalSchematicandWireHarness
Drawings/DiagramsinAppendixA(pageA–1).
10.Securetherelaytothemountingbracketandconnectthewireharness
electricalconnectortotherelay.
11.Connectthepositive(+)cabletothebatteryandthenconnectthenegative
(-)cabletothebattery;refertoServicingtheBattery(page5–94).
ElectricalSystem:TestingtheElectricalComponents
Page5–70
Groundsmaster
®
4300-D
16226SLRevC