Wiring Harness (Short Circuit) - Test
短路是一种可以导致意外电流的电路故障。 通常，短路是指绕过负载电路。 指示灯电路导线之间短路会在导线中产生过大电流，但指示灯上却没有电流。 指示灯短路。 正常电路中的电阻值可能会发生变化，但是特定电路与其他无关电路之间的电阻值始终大于 5K Ω。 下述步骤将说明短路测试：
参考有关完整的电气示意图，参考正在维修的机器的电气系统示意图, RENR9783。
测试是否存在短路
Show/hide table
| 故障排除测试步骤 | 数值 | 结果 |
|---|---|---|
| 1. 确定短路。 A. 确定可疑电路中的接头和导线编号。 使用机器的电气系统示意图检查电路。 B. 将钥匙起动开关和断路开关转至断开位置。 C. 从配线线束上断开部件和 ECM。 D. 在 ECM 的机器线束接头上，将一支万用表表笔放在可疑导线的触点上。 E. 使用另一支万用表表笔检查 ECM 接头中的所有其他触点与机架接地之间的电阻。 |
所有电阻读数均大于 5K Ω。 |
正常：线束电路正常。 停止 不正常：电阻小于 5 Ω。 机器线束中存在短路。 可疑导线与具有最低电阻测量值的导线之间短路。 修理：修理或更换机器线束。 注：电阻大于 5 Ω 但小于 5K Ω 表示电路中的连接松动或腐蚀。 电阻测量值大于 5K Ω 表示电路中存在断路。 停止 |
Caterpillar Information System:
C27 and C32 Engines for Caterpillar Built Machines Gear Group (Rear)
C27 and C32 Engines for Caterpillar Built Machines Camshaft
993K Wheel Loader C32 Engine Supplement Engine - Install
966K Wheel Loader Electrohydraulic System Monitoring System (Hydraulic Functions)
312D2 and 313D2 Excavators Specifications
The Rear Differential Ring Gear Needs Inspected on Certain 627H Wheel Tractor-Scrapers{3256, 3258} The Rear Differential Ring Gear Needs Inspected on Certain 627H Wheel Tractor-Scrapers{3256, 3258}
C27 and C32 Engines for Caterpillar Built Machines Exhaust Manifold
C27 and C32 Engines for Caterpillar Built Machines Piston and Rings
2012/08/30 New Track Carrier Roller Is Now Used on Certain D6K Track-Type Tractors {4150, 4154}
2012/09/03 A New Procedure To Flush The Elevator System Is Now Available On 623H Wheel Tractor-Scrapers {6210}
993K Wheel Loader Wiring Harness (Open Circuit) - Test
The Air Conditioning Performance Can be Improved by The Installation of a Baffle Arrangement on Certain 621H, 623H, and 627H Wheel Tractor-Scrapers{7320} The Air Conditioning Performance Can be Improved by The Installation of a Baffle Arrangement on Certain 621H, 623H, and 627H Wheel Tractor-Scrapers{7320}
Reinforcing the Right-Hand and Left-Hand Fenders On the D11R/T{0679, 7252, 7254} Reinforcing the Right-Hand and Left-Hand Fenders On the D11R/T{0679, 7252, 7254}
D5R Track-Type Tractor TA2 Technical Inspection{7000, 753T} D5R Track-Type Tractor TA2 Technical Inspection{7000, 753T}
AD60 Underground Articulated Truck Machine Electrical System Hydraulic Fan System (Power Train)
AD60 Underground Articulated Truck Braking System Brake Accumulator
C27 and C32 Engines for Caterpillar Built Machines Valve Mechanism Cover
C27 and C32 Engines for Caterpillar Built Machines Rotary Actuator - NOx Reduction System
C27 and C32 Engines for Caterpillar Built Machines Gear Group (Front)
C27 and C32 Engines for Caterpillar Built Machines Gear Group (Rear)
C27 and C32 Engines for Caterpillar Built Machines Flywheel Housing
2012/10/26 An Improved Method of Attaching Fuel Pressure Sensor Harness to the Engine of Certain 980H Wheel Loaders Is Now Used {1261, 1262, 1408}
C27 and C32 Engines for Caterpillar Built Machines Flywheel Housing
Bronze 415-8631 Engine Overhaul Kit for 3176 Machine Engines{1000} Bronze 415-8631 Engine Overhaul Kit for 3176 Machine Engines{1000}