Instrument Cluster. Table of Contents

Transcription

1 Instrument Cluster Table of Contents Sub-Headings Safety 2 Warnings 2 Cautions 2 s 2 Introduction 2 Removal of Instrument Cluster 2 Light Bulb Replacement 2 Instrument Replacement (Except Speedometer or Tachometer 3 Installation of Gauges 3 Speedometer Replacement 4 Installation of Tachometer 6 Figures Figure 1 Typical Instrument Light Assembly 2 Tables Table 1 Michelin 5 Table 2 Bridgestone and Goodyear 5 Table 3 Gauge Specifications 6 Table 4 Transmission Oil Temperature 6 Table 5 Engine Oil Pressure 6 Table 6 Fuel Gauge 6 Section 110 Instrument Cluster 1

2 Instrument Cluster Safety The purpose of this safety summary is twofold. First, it is to help ensure the safety and health of individuals performing service on, or operation of, the Blue Bird TC Series bus. Second, it is to help protect equipment. Before performing any service or operating procedure on the TC bus, individuals should read and adhere to the applicable warnings, cautions and notes located throughout this Blue Bird Service Manual. Warnings Warnings apply to a procedure or practice that, if not correctly adhered to, could result in injury or death. Particular attention should be paid to sections of this manual where warnings appear. Cautions Cautions apply to a procedure or practice that, if not correctly adhered to, could result in damage to or destruction of equipment. Removal of Instrument Cluster The instrument cluster panel must be removed to perform any maintenance or to change light bulbs, etc. 1. Remove the 8 machine screws. 2. Carefully tip the instrument cluster top toward you, being careful not to disconnect any connectors or break any wires. 3. Allow the instrument cluster to lie against the steering column. Light Bulb Replacement There are 2 connectors at the termination of each light bulb. Some of the instruments in the panel have 2 light bulbs for illumination. Either (or both) can be "burned out" at any given time. The light bulb is similar to an ornamental light bulb, but a bit larger. 1. Grasp the light bulb holder (2) firmly, and pull straight out. Do not twist. Figure 1. s s are used to explain, clarify or otherwise give additional insight for a given subject, product or procedure. Please note that on occasion, notes, too, may advise of potential safety issues. Introduction This service manual was written using a Blue Bird TC Series bus with a Cummins ISB engine and an Allison 545 transmission. We have chosen the typical options package for this section. The instrument panel you are working on could vary in detail, but will be similar, if not identical. Caution Be sure the ignition switch is in the "OFF" position and the key is removed from the ignition before continuing. Figure 1 Typical Instrument Light Assembly 2 Section 110 Instrument Cluster

3 2. With the bulb holder (2) out of the instrument, pull the bulb (1) straight out of the holder. The light bulb has 2 thin wires bent upwards (1 on either side) to make electrical contact. Figure 1. If there are 2 tabs opposite the tip of the bulb, you have separated the light bulb holder from the wiring harness. Grasp the glass end of the light bulb and pull straight out to remove the bulb from the holder. 3. Replace the light bulb (1). Be careful to arrange the contact wires with 1 wire on each side of the bulb, and observe that they are straight. 4. If the light bulb holder was disconnected from the wiring harness, install the holder to the harness. 5. Turn the ignition switch to the "ON" position, and the instrument panel light switch to the "ON" position, to test that the new light bulb illuminates. 6. Carefully install the light bulb holder into the instrument. 7. Replace the instrument cluster, being careful not to break, pinch, crimp, or disconnect any wires. 8. Replace the 8 machine screws to install the instrument cluster panel. Be careful not to over tighten the machine screws. Instrument Replacement (Except Speedometer or Tachometer) Each gauge or instrument in the instrument panel can be replaced, as well as the rocker switches. These instructions are typical of all the instruments in the panel, although the connections to the function being monitored may vary, depending on the measurement being displayed. 1. Remove the 8 machine screws around the parameter of the instrument panel. 2. Lift the instrument panel up and out of the dash mount, being careful not to break any wires or connections. 3. Allow the instrument panel to rest against the steering column. 4. Disconnect the wiring harness from the instrument being replaced, including the light bulb holder. If more than 1 instrument is to be removed from the instrument panel, carefully label each connector for re-assembly. 5. Firmly grasp the plastic "ring-nut" and turn counter-clockwise to remove the instrument. Figure Lay the "O" ring aside for possible reuse. Installation of Gauges To install the new or repaired instrument, observe that the gauge is positioned properly before continuing. Figure Install the instrument through the instrument panel. 2. Place the "O" ring over the instrument from the rear. 3. Thread the "ring-nut" (3), or hand tightener, onto the instrument and spin down to just make contact with the "O" ring. 4. Carefully hold the instrument in the correct position, as seen from the driver's view, and hand tighten the ringnut to approximately 2 ft-lbs. (2.7 Nm). Caution Do not over tighten the ring-nut, or the threads will be stripped. However, the nut must be tight enough to prevent the instrument from changing position during normal operation of the vehicle. Section 110 Instrument Cluster 3

4 5. Install the monitor wiring harness. 6. Install the light bulb holder. 7. Install the instrument panel into the dash mount, being careful not to break, pinch, crimp, or disconnect any wires. 8. Replace the 8 machine screws to install the instrument cluster panel. Be careful not to over tighten the machine screws. Speedometer Replacement The instrument panel must be removed according to instructions 1 through 4 above under "Instrument Replacement". Installation of the speedometer is virtually the same as the replacement of the other instruments in the panel. A new speedometer must be calibrated. The speedometer must be calibrated if the rear wheel tire characteristics are changed. The following steps accomplish calibration of the speedometer. 1. Calculate the correct number of pulses per mile for the vehicle: All TC Series buses have a transmission pulse of 16. Find the correct number of revolutions per mile for the tires on the vehicle. Table 1 or Table 2. Record and Chassis Service Number plate, located front upper inner panel, above the windshield. Example All TC Series transmission factor = 16. Our hypothetical bus is mounted with Michelin, 275/80R 22.5G tires. The tread design is PXZA-1, so the revolutions per mile are 516. Table 1. From the Axle Record and Chassis Service plate, we find the axle ratio is The calculation is as follows. (16) X (516) X (5.38) = The speedometer is set using whole numbers only. For this reason, the last digit in the number that flashes will always be zero. Therefore, the number that appears during the test should be set to With the new speedometer installed per the above instructions, depress and hold the speedometer button. It is located on the lower face plate. 2. Turn the ignition "ON". Do not start the engine. 3. When "PULSE" appears on the LCD display, release the button. 4. After a few seconds, a number will flash on the LCD display. This number is the number of pulses per mile. 5. As each digit flashes, depress and hold the speedometer button until the correct number appears. If the vehicle is mounted with tires other than those listed in the tables, contact your tire dealer for the accurate number of revolutions per mile. Find the rear axle ratio for the vehicle, recorded on the Axle 4 Section 110 Instrument Cluster

5 Michelin SIZE TREAD REVOLUTIONS/MILE 10R 22.5G XZE R 22.5G XM+S R 22.5G XZA R 22.5H XZE R 22.5H XZA R 22.5H XM+S /70R 22.5 XZE /80R 22.5G XZE /80R 22.5G PXZA /80R 22.5G PXDHT /80R 22.5H XZA /70R 19.5G PXZA /70R 19.5G PXZT /80R 22.5L PXZA R 22.5H XYZ R 22.5H XZ2 490 Table 1 Michelin Bridgestone SIZE TREAD REVOLUTIONS/MILE 10R 22.5G R R 22.5G M R 22.5H R R 22.5H R R 22.5H M /75R 22.5G R299-LP /75R 22.5G M711-LP R 22.5H R /75R 22.5J R /75R 22.5 R294LP R 22.5H M Goodyear 10R 22.5G G R 22.5G G R 22.5G G R 22.5G G159A R 22.5H G167A R 22.5H G R 22.5H G R 22.5H G159A /75R 22.5G G /75R 22.5G G159A /75R 22.5G G167A /70R 19.5G G /70R 19.5G G Table 2 Bridgestone and Goodyear Section 110 Instrument Cluster 5

6 Installation of Tachometer The tachometer is removed and installed in an identical manner to the above instructions for the speedometer. The tachometer is calibrated for the engine though, so only instruments purchased from Blue Bird should be used. Some other model VDO tachometers will fit the instrument panel, but they may not be calibrated to the engine option installed in your vehicle at the time of manufacture. Gauge Specifications Water Gauge Measuring Range 100 to 250 F F Deflection Ω Table 3 Water Gauge Transmission Oil Temperature F Deflection Ω Table 4 Transmission Oil Temperature Gauge Engine Oil Pressure PSIG Deflection Ω Table 5 Engine Oil Engine Oil Pressure PSIG Deflection Ω Table 5 (Continued) Fuel Gauge Range Empty to Full Indication E 1/8 1/4 3/8 1/2 5/8 3/4 7/8 F Deflection Ω Table 6 Fuel Gauge Back to Top 6 Section 110 Instrument Cluster