GASOLINEVEHICLE-TROUBLESHOOTING
ANDELECTRICALSYSTEMTestProcedures
18
TESTPROCEDURES
Usingthefollowingprocedures,theentireelectricalsystemcanbetestedwithoutmajordisassemblyofthevehicle.
WARNING
•Ifwiresareremovedorreplaced,makesurewiringandwireharnessisproperlyroutedandsecured.
Failuretoproperlyrouteandsecurewiringcouldresultinvehiclemalfunction,propertydamage,
personalinjury,ordeath.
Forsometests,theelectricalcomponentboxcovermustberemovedtogainaccesstothevariouscomponentsthat
aremountedinsidethecomponentbox.SeefollowingWARNING.
WARNING
•Shortingofbatteryterminalscancausepersonalinjuryordeath.
Aftertestproceduresarecompleted,besuretoreplacethecover.SeefollowingCAUTION.
CAUTION
•Exposuretowaterandtheelementsmaydamageelectricalcomponents.Donotoperatevehicle
withoutthecoverproperlyinstalled.
TESTINGBASICS
•Batteryvoltagewillbereferencedthroughoutthetestprocedures.BatteryvoltageisaccessedintheBatterytest
procedure.
•TheMaintenace/Operateswitch,intheMAINTENANCEposition,groundsandkillstheignitionifthe
Forward/Neutral/Reversecontrol(FNR)isplacedinForR.
•ThekeyswitchpowerstheECU,fuelpump,solenoid,lights,andtheconnectedcardevice.
•The2-ampfuseispoweredbythekeyswitchviathe10-ampATMfuseandcarriesbatteryvoltagetotheconnected
cardevice.
•Theterm“back-probe”referstoprobingthesideofaconnectorthatthewireenters.Thisisusuallydonewhen
theconnectormustremainconnectedtoadevice.Analternativemethodistouseaninsulation-piercingprobe.
SeefollowingCAUTION.
CAUTION
•Becarefulnottodamagethewireorterminalwhenback-probing.
•Whentestingvoltage,thebatterymustremainconnected.
•Whentestingvoltage,unlessspecicallydirectedtodootherwiseinaprocedure,connecttheblack(–)probeofthe
multimetertochassisground.
•Whentestingresistanceorcontinuity,turnoffpowertothecircuitbeingmeasuredanddischargeanycapacitor.The
presenceofvoltagecancauseinaccuratereadings.
2020Precedent,Villager2and4MaintenanceandServiceManualPage18-7