When the internal wiring harness problem occurs, because the external insulation package, it is not easy to determine the exact location of broken, but if the use of digital multimeter, you can easily find the location of the broken line.
1, the emergence of a breakpoint of the car harness end of the line connected to the 22V fire line, while the other end is floating.
2, the location of the access point in the line of fire about 15 inside the place is the breakpoint of the location of the harness.
3, move the red test pen, red pen to move to a certain place, the display above the voltage will suddenly drop to zero o'clock, about the original voltage of about one-tenth.
4, the digital multimeter pulled AC2V file that place, from the car harness line of fire line access side, with one hand pinch the black pen pen tip, and the other hand is the red pen along the wire insulation Slow to move, this time the display shows the voltage value is about 0.445V or so.