Komatsu WA500-7 Wheel Loader Service Manual

Table of Contents

• Index and Foreword
• Specification
• Structure, functions and maintenance standard
• Standard Value Table
• Testing and Adjusting
• Troubleshooting
• Disassembly and Assembly
• Maintenance Standard
• Appendix
• Diagrams and Drawings
• Index

Backup lamp and brake lamp

1. From battery relay
2. Fuse box 1
3. Brake lamp switch
4. Brake lamp relay
5. Brake lamp (L.H.)
6. Brake lamp (R.H.)

Operation (WA500-G7B0-044-K-00-A)
• When the brake pedal is depressed, the brake lamp switch contacts close and a current flows into the
brake lamp relay coil to close the relay contacts, and then the following circuit is formed and the right and
left brake lamps light up; Fuse → brake lamp relay terminal 3 o terminal 5 o right and left brake lamps o
ground.
• When the brake pedal is released, the contacts of the brake lamp switch contacts open and the brake
lamp relay contacts open to turn the brake lamps OFF.
• The current flows into the brake lamp circuit when the battery relay operates, thus the brake lamps do not
light up while the starting switch is in the OFF position.