Guardian Technologies 4270 manual Test 32- Test Preheat Contactor, Test 33- Test Glow Plugs

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Section 7

DIAGNOSTIC TESTS

6.Place test leads on each end of wire, continuity should be measured.

7.If continuity is measured, test battery voltage on Wire 14 going to circuit board on Pin 10, with prime switch pressed. Meter should read battery voltage.

8.Set a VOM to measure resistance.

9.Place a test lead on the terminal of the fuel solenoid where Wire 14 was previously located. Place the other test lead to clean ground, meter should read 12.4 ohms.

RESULTS:

1.If battery voltage is not measured in step 4, and continuity is measured in step 6 and battery voltage is measured in step 7, than replace the circuit board.

2.If infinity is measured in step 6, replace wire.

3.If battery voltage is not measured in step 7, work back to previ- ous test on flow chart.

4.If continuity is measured in step 9, replace solenoid.

5.If 12.4 ohms was measured in step 9, proceed to next test on flow chart.

TEST 32- TEST PREHEAT CONTACTOR

DISCUSSION:

If battery voltage is available to the preheat contactor via Wire 150 and the glow plugs and fuel pump do not work, a possibility could be a failed contactor.

PROCEDURE:

1.Set a VOM to measure continuity.

2.Disconnect Wire 0 from the preheat contactor.

3.Place one test lead on the previously disconnected Wire 0 and the other to clean ground. Continuity should be measured.

4.Set a VOM to measure resistance.

5.Disconnect Wire 150 and 0 from the preheat contactor (front terminals).

6.Place one test lead to the terminal where Wire 150 was previ- ously disconnected, and the other test lead where Wire 0 was previously disconnected.

7.Place a jumper lead from Wire 15 (battery positive) to the ter- minal where Wire 150 was previously. Prime function should occur.

RESULTS:

1.If infinity is measured in step 3, repair or replace Wire 0 and retest.

2.If resistance is incorrect in step 6, then replace preheat contactor.

3.If prime function did not occur in step 7, and resistance was incorrect in step 6, proceed to next test on flow chart.

TEST 33- TEST GLOW PLUGS

DISCUSSION:

Once the preheat contactors contacts close, positive battery voltage from Wire 13 to Wire 157 will power the glow plugs.

PROCEDURE:

1.Set a VOM to measure resistance.

2.Disconnect Wire 157 from glow plugs.

3.Place positive (+) test lead to center electrode, and the nega- tive (-) test lead to ground. Resistance should be 1.0 ohm.

4.If resistance is good, remove glow plug from engine. Inspect the sheath for damage.

RESULTS:

1.If sheath is chipped or broken, replace glow plug.

2.If resistance and sheath are good, proceed to next step on flowchart.

TEST 34- TEST D1 DIODE

DISCUSSION:

The D1 diode is a protective device that prohibits the return flow of DC current to the glow plugs while the unit is running. If this diode is bad or shorted to ground, power will not be available to Wire 14 off the other end of the diode. If Wire 14 does not receive voltage, the fuel solenoid, fuel pump, and hourmeter will not operate.

PROCEDURE:

1.Set a VOM to measure continuity.

2.Place the test leads on each end of the diode, then reverse the leads to the opposite ends. Continuity should be measured only in one direction.

RESULTS:

1.If continuity is measured in both directions, replace the diode.

2.If diode checks good, then battery voltage should be measured on Wire 14 to the board on Pin 10. If it is not measured, then Wire 14 needs to be replace.

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Contents Diagnostic Repair Manual Safety Replacement PartsTable of Contents 57-59 Magnetism Electromagnetic FieldsElectromagnetic Induction Simple AC Generator More Sophisticated AC GeneratorGenerator Operating Diagram Field Boost Generator AC Connection SystemLine Breakers 120 VAC only Connection for 120/240 VAC Dual Voltage Rotor Assembly LIC Grit or Abrasive to Clean Slip RingsExcitation Circuit Components Battery Charge ComponentsBrush Holder General162 Adjust POT LEDAdjustment Procedure Voltage RegulatorControl Panel Component Identification Control Panel ComponentsDrying the Generator Cleaning the GeneratorEffects of Dirt and Moisture Insulation Resistance TestersCloth or Compressed AIR Brushing and Vacuum CleaningStator Insulation Resistance Stator SHORT-TO-GROUND TestsTesting Rotor Insulation MegohmmeterMeasuring AC Voltage MetersVOM Measuring DC VoltageMeasuring AC Frequency Measuring CurrentMeasuring Resistance Electrical Units Ohms LAWIntroduction Operational AnalysisCircuit CONDITION- OFF Circuit CONDITION- PRE-HEAT Circuit CONDITION- Cranking Circuit CONDITION-RUNNING Circuit CONDITION- Shutdown Circuit CONDITION- Fault Shutdowns Battery Engine Control Circuit BoardCharging a Battery Effects of TemperatureChecking Battery State of Charge Adding WaterAMP Fuse Preheat SwitchSTART/STOP Switch Starter Contactor & MotorFuel NOZZLES/INJECTORS Engine GovernorFuel Injection Pump Glow PlugsEngine Protective Devices LOW OIL Pressure Switch High Coolant Temperature SwitchAdapter LOW OIL Pressure Switch Overspeed ProtectionTroubleshooting Flowcharts Troubleshooting Flowcharts Problem 3 No Battery Charge Output Troubleshooting Flowcharts Troubleshooting Flowcharts Troubleshooting Flowcharts Troubleshooting Flowcharts Troubleshooting Flowcharts Test 2 Check & Adjust Test 1- Check NO-LOAD Voltage FrequencyTest 3- Test Excitation Circuit Breaker Test 4- Fixed Excitation TEST/ROTOR AMP DrawTest 6- Check Field Boost Test 5- Wire ContinuityRe-connect Wire 11 and Wire 22 to the Voltage Regulator Set a VOM to its Rx1 scaleTest 7 Test Stator DPE Winding Model QP75D159W Test 8- Check Sensing Leads / Power WindingsTest 9- Check Brush Leads 184WTest 11- Check Rotor Assembly Tance Tests ProcedureTest 10 Check Brushes & Slip Rings Test 13- Check Load Voltage Frequency Test 15 Check Battery Charge OutputTest 12 Check Main Circuit Breaker Test 14- Check Load Watts & AmperageTest 16 Check Battery Charge Rectifier Battery Charge Rectifier BCR is a full wave rectifierShort to Ground Test 18 TRY Cranking the Engine Test 19- Test PRE-HEAT SwitchSet a VOM to read battery voltage 12 VDC Test 20- Check Fuel PumpDisconnect the connector from the wires of the fuel pump Test 22- Check Battery & CablesTest 23- Check Power Supply to Circuit Board Test 21- Check 14 AMP FuseTest 24 Check START-STOP Switch Not ActivatedTest 26- Test Starter Contactor Test 27 Check Starter MotorConditions Affecting Starter Motor Performance Tools for Starter Performance Test Checking the PinionPinion Measuring CurrentTest Bracket Testing Starter MotorTachometer Starter motor test bracket may be made as shown in FigureIf Wire 18 checks GOOD, proceed to Problem 8 Section Test 29 Check Wire 14 Power SupplyTest 30 Check Wire Test 28- Check Fuel SupplyTest 32- Test Preheat Contactor Test 33- Test Glow PlugsTest 34- Test D1 Diode Test 35- Check Valve Adjustment Remove the valve cover from engine Disconnect the batteryTest 36- Fuel Injector Pump Down Test / Compression Test If fuel is noted, proceed to next step in flowchartAdjust the regulated pressure on the gauge to 80 psi Repeat Steps 1 through 8 on remaining cylinderTest 38 Check OIL Pressure Switch Test 40- Test Water Temperature SwitchTest 39- Check Circuit Board for Ground Test 43 Check Wire 15 for Short to Ground If continuity is measure, replace the switchComponents for Short to Ground Major Disassembly RE-ASSEMBLY Belt TensioningLine Corner UP Between 5˚ to 10˚ FAN BeltSection Exploded Views / Part Numbers Flywheel Assembly Rotor AssemblyStator Assembly Bearing Carrier, FrontBase Frame Drawing No D2357-A Base Frame Weldment Door, Service RearDoor, Service Front Slide Latch FlushEnclosure Drawing No D2358-D Gasket, Electrical Access Cover, Access LiftCover, Access Electrical Decal, Battery +Views / Part Cover Plate, Scroll Weldment 25 26 Rectifier, Battery Charging Assembly, Potted RegulatorAssembly Marine Control Board Wire Assembly #Intake and Exhaust System Drawing No D2362-B Air Filter Exhaust GasketChamber Air Intake Hose, Air InletViews / Part Numbers Cable, Battery Fuel Pump AssemblyBoot, Battery Cable Wire Assembly, Black #4 GroundCustomer Controls Assembly Drawing No D2364-D Boot / Nut / Preheat Switch Start / Stop SwitchSwitch, Pushbutton Spst Boot, Circuit BreakerKEY Camshaft AssemblyCamshaft Gear Gear2630 Liter Diesel Cylinder Head Drawing No D2794 Liter Diesel Crankshaft, Piston and Flywheel Drawing No -B Thrust Washer Idler Gear AssemblySpring OIL Pump CoverIntake Rocker ARM Rocker ARM AssemblyIncludes ALL Components Shown below Exhaust Rocker ARMLiter Diesel Injector Pump Drawing No -C Tank Return Model 04270 To Injection Pump To Fuel Pump 27 25 19 18 HOUSING, Timing Gear 3114 Liter Diesel Water Pump Drawing No Charts Engine Specifications Generator SpecificationsROTOR/STATOR Resistance Values Type Quietpact ModelPage Data Data Electrical Data Schematic Drawing No C4945-A Model C4945Electrical C4946-ASheet 2 OF4996 REV. O
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