CARRIER AS-INNER 20R1874 - Caterpillar

2. TOP TANK - When possible, pipe plug location in the radiator top tank. Otherwise, sensor bulb indicator location in the regulator housing or water manifolds. 3. BOTTOM TANK -Radiator drain outlet or pipe plug location i radiator lower elbow.4. TORQUE CONVERTER - Sensor bulb indicator location in torque converter outlet. 5. TRANSMISSION - Lube valve tap, lube line tap or oil filter tap.6. ENGINE LUBRICATION OIL - Engine block oil distribution gallery. 7. REGULATOR - Sensor bulb indicator location. 8. RETARDER - Sensor bulb indicator location.9. HYDRAULIC OIL - Hydraulic tank, pump or line connecting the pump and the control valve. The probe can be installed in the lines leading from the control valve but the oil must be cycled until stabilized at system temperature to get an accurate reading. 10. TRUCK OIL DISC BRAKES (HYDRAULIC OIL) - Sensor bulb indicator location in hydraulic tank.(3) Check the 5P1719 Meter to make sure it is on zero with the power off. Adjust the Thermistor Thermometer battery voltage prior to each using. Rotate selector knob (8) to "V. ADJ." and align needle with the mark on the meter face by turning slotted screw (9).(4) Refer to the following chart which lists system areas to be compared, expected temperature readings, problems and probable causes of the problems. To obtain accurate readings, measure temperatures during actual working conditions. If the machine is being tested in a rainstorm or partially submerged in water, the electrical connectors will tend to short out. To prevent this, apply a liberal quantity of 4L7464 Silicone Grease to the electrical connectors before the cable is attached to the thermistor probe.Calibration Instructions
The following conditions will make it necessary to calibrate the thermometer readout: Three to six months use of the Thermistor Thermometer; replacement of the 5P1719 Meter; Thermistor Thermometer has been dropped or otherwise damaged.(1) To calibrate the Thermistor Thermometer read-out, turn selector knob (8) to "OFF". The needle should be within one increment of the 32°F (0°C) mark. Turn slotted screw (10) until the needle is properly aligned.(2) Adjust the battery voltage. Rotate selector knob (8) to "V.ADJ." and align the needle with the mark on the meter face by turning slotted screw (9).(3) Remove the panel from its case. Using a 1% tolerance resistor with a rating of 2000 ohms, rotate selector knob (8) to an input position and connect the resistor to the corresponding input jack as shown. The meter should read 213.5-214.5°F (100.7-101.3°C).(4) If the temperature reading in step 3 is inaccurate, adjust potentiometer (11) to get the correct calibration. Use an additional 10.00K 1% resistor to check instrument linearity. This resistor should produce a reading of 123.5-129.5°F (50.8-54.1°C). If not, replace the 5P1719 Meter.Troubleshooting The Electrical Components
This section is written as an aid for troubleshooting the Thermistor Thermometer for electronic technicians only. It must not be used by service personnel with no training or knowledge of electronics. A circuit board illustration is included showing the position of each of the components.