Toro 30344 - Page 281

TestingtheHighTemperatureWarningSwitch(continued)
DANGER
Iftheradiatororengineishot,pressurizedhotcoolantcanescape
andcauseburns.
Donotopentheradiatorcapordraintheradiatorwhenthecoolant
ishot.Ensurethattheengineiscoolbeforeremovingthehigh
temperaturewarningswitchfromtheengine.
3.Lowerthecoolantlevelintheengine.
4.Removethewireharnessconnectorfromthehightemperaturewarning
switch,andremovetheswitchfromtheengine.
g226814
Figure153
5.Puttheendoftheswitchinacontainerofoilwithathermometerandthen
slowlyheattheoil(Figure153).
CAUTION
Theoilishotandcouldcausepersonalinjuryorre.
Handlethehotoilwithextremecare.
Note:Beforetakingthesmallresistancereadingswithadigitalmultimeter,
shortthemultimetertestleadstogether.Themeterwilldisplayasmall
resistancevalue(usually0.5ohmsorless).Thisresistanceisbecauseofthe
internalresistanceofthemultimeterandtestleads.Subtractthisvaluefrom
themeasuredvalueofthecomponentyouaretesting.
6.Checktheresistanceoftheswitchwithamultimeter(ohmssetting)astheoil
temperatureincreases.
A.Themetershouldindicatemorethan600ohmsat21°C(70°F).
B.Themetershouldindicateapproximately460ohmsat38°C(100°F).
C.Themetershouldindicatefrom54to78ohmsat93°C(200°F).
7.Iftheswitchdoesnotmeetthespecications,replacetheswitch.
Groundsmaster
®
3280-D/3320
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ElectricalSystem:TestingtheElectricalComponents
05138SLRevB