Service and Repair Manual September 2018Manifolds90 S® -60 XC ™ • S® -65 XC ™ Part No. 1288652GT7-11Valve CoilsHow to Test a CoilA properly functioning coil provides anelectromotive force which operates the solenoidvalve. Critical to normal operation is continuitywithin the coil. Zero resistance indicates the coil hasfailed.Since coil resistance is sensitive to temperature,resistance values outside specification can produceerratic operation. When coil resistance decreasesbelow specification, amperage increases. Asresistance rises above specification, voltageincreases.While valves may operate when coil resistance isoutside specification, maintaining coils withinspecification will help ensure proper valve functionover a wide range of operating temperatures.Electrocution/burn hazard.Contact with electrically chargedcircuits could result in death orserious injury. Remove all rings,watches and other jewelry.1 Tag and disconnect the wiring from the coil tobe tested.2 Test the coil resistance.Result: The resistance should be withinspecification, plus or minus 30%.Result: If the resistance is not withinspecification, plus or minus 30%, replace thecoil.Valve Coil ResistanceSpecificationNote: The following coil resistance specificationsare at an ambient temperature of 68°F / 20°C. Asvalve coil resistance is sensitive to changes in airtemperature, the coil resistance will typicallyincrease or decrease by 4% for each 18°F / 10°Cthat your air temperature increases or decreasesfrom 68°F / 20°C.Description SpecificationSolenoid valve, 10V DC (schematic items E,F, S, T and KK)4 ΩSolenoid valve, 10V DC (schematic item A, K,AH, AS and GB)5 ΩProportional solenoid valve, 12V DC(schematic items C, G and R)3.7 ΩProportional solenoid valve, 12V DC(schematic item M and N)7.2 Ω
