GENERATOR AR 7C3548 - Caterpillar

General Fault Diagnosis
If problems are encountered, they should be corrected promptly to maintain an effective, efficient machine. Only qualified personnel should repair and adjust the machine.Use this section as a reference to help locate and correct problems.This listing will not give all possible problems, causes and corrections. The serviceman must find the problem and its source, then make the necessary repairs.The listing of problems, causes and corrections in this section only gives an indication of where a possible problem can be, and what repairs maybe needed. 1. No Flow Indicated At Flowmeter Or Totalizer With No Flow From Asphalt Emulsion Pump Cause: Rate of flow selector set too low. Correction: Set selector up to specification. Cause: Fuse - defective. Correction: Replace fuse. Cause: No power to control module. Correction: Check power cable terminals. Cause: Servo valve solenoid shorted/open. Correction: Replace servo valve. (Operate on manual override). Cause: No signal from ground sensor. Correction:a) Check ground sensor.b) Check power cable. 2. No Flow Indicated At Flowmeter But Asphalt Emulsion Pump Continues To Provide Flow Cause: Defective flow rate indicator. Correction: Replace. Cause: Defective or loose coupling between pulse generator assembly and rate of flow indicator. Correction: Tighten or replace as required. 3. No Flow From Asphalt Emulsion Pump in the Automatic Mode Cause: No voltage at servo valve or servo valve defective. Correction:a) Check fuse. Replace if necessary.b) Check voltage input at control module. Voltage should be 12 VDC.c) If no voltage is present, check battery power supply, terminal connections and power cable.d) Voltage required to activate the servo valve is 2 1/2 to 3 VDC. With all other conditions acceptable, but obtaining no output to the servo, the problem is in the control module. Replace.e) If voltage output to the servo valve is acceptable, proceed to check the cable.f) If the cable is in good condition, the solenoid in the servo is defective, requiring replacement of the servo. Continue operation with manual override. 4. Full Flow Indication At Flowmeter Cause: No signal from meter sensor. Correction: Meter sensor. Cause: No power to flow sensor. Correction: Check meter sensor cable. 5. Asphalt Emulsion Continues To Flow When Machine Stops Cause: Servo valve stuck in open position. Correction: Remove servo valve and clean. Cause: Same as 4 above. Correction: Same as 4 above. Cause: Manual override is controlling rather than control module. Correction: Reset manual override. 6. No Flow From Asphalt Emulsion Pump With Voltage Signal At Servo Valve Above 3 VDC Cause: Solenoid shorted or open at servo valve. Correction: Replace servo valve. Order replacement but continue to use manual override feature of servo valve until replaced. 7. No Flow From Asphalt Emulsion Pump With Manual Override Controlling Output Cause: Servo valve malfunction. Correction: Replace servo pressure valve. Cause: Hydraulic system malfunction. Correction: Check hydraulic system pressure. Replace defective hydraulic system components. 8. System Accuracy Is Not To Job Specification Cause: Nozzle size too large or too small for specific requirement. Correction: If flow is too low, go to