Method and apparatus for measuring a parameter of a vehicle electrical system

Abstract

A vehicle electrical system tester for testing the electrical system of a vehicle is provided. The electrical system has a wiring harness which extends between components of the vehicle and includes a plurality of wires. The vehicle electrical system tester is configured to measure an electrical parameter of at least one of the plurality of wires through a first connection to coupled to a first end of the at least one of the plurality of wires and a second connection coupled to a second end of the at least one of the plurality of wires. An electrical signal is applied between the first and second ends of the at least one of the plurality of wires and the electrical parameter of the at least one of the plurality of wires is responsively measured.

1 . A vehicle electrical system tester for testing the electrical system of a vehicle, the electrical system having a wiring harness which extends between electrical components of the vehicle, the wiring harness including a plurality of wires, the vehicle electrical system tester configured to measure an electrical parameter of at least one of the plurality of wires and comprising:
 a first connection configured to couple to a first end of the at least one of the plurality of wires of the wiring harness;   a second connection configured to couple to a second end of the at least one of the plurality of wires of the wiring harness;   test circuitry coupled to the first and second connections, the test circuitry applying an electrical signal between the first and second ends of the at least one of the plurality of wires and responsively measuring the electrical parameter of the at least one of the plurality of wires of the wiring harness.   
     
     
         2 . The vehicle electrical system tester of  claim 1  including a connection to a battery of the vehicle and wherein the measured parameter is further based upon a measurement made through the connection to the battery. 
     
     
         3 . The vehicle electrical system tester of  claim 1  including an electrical connection to a battery of the vehicle and wherein circuitry of the vehicle system electrical tester is powered with power from the battery. 
     
     
         4 . The vehicle electrical system tester of  claim 1  wherein the test circuitry is further configured to provide an output to an operator, the output to the operator assisting the operator in identifying the second end of the at least one of the plurality of wires of the wiring harness. 
     
     
         5 . The vehicle electrical system tester of  claim 4  wherein the output comprises a tone. 
     
     
         6 . The vehicle electrical system tester of  claim 5  wherein the test circuitry applies a tone signal to the first end of the wire and the tone signal is received by the second connection. 
     
     
         7 . The vehicle electrical system tester of  claim 1  including an input configured to receive information from an operator related to at least one of the components of the vehicle coupled to the first end of the at least one of the plurality of wires of the wiring harness. 
     
     
         8 . The vehicle electrical system tester of  claim 7  including a user output displaying a plurality of vehicle components and wherein the operator selects a vehicle component coupled to one end of the at least one of the plurality of wires of the wiring harness from the plurality of components through a user input. 
     
     
         9 . The vehicle electrical system tester of  claim 1  wherein the signal comprises a DC signal. 
     
     
         10 . The vehicle electrical system tester of  claim 1  wherein the signal comprises a AC signal. 
     
     
         11 . The vehicle electrical system tester of  claim 1  wherein the parameter relates to the ability of the at least one of the plurality of wires to carry digital data. 
     
     
         12 . The vehicle electrical system tester of  claim 1  including a user output and wherein the test circuitry prompts an operator to disconnect at least one end of the plurality of wires from the vehicle electrical system through the user output. 
     
     
         13 . The vehicle electrical system tester of  claim 1  wherein the first and second connections comprise Kelvin connections. 
     
     
         14 . The vehicle electrical system tester of  claim 1  wherein the first connection comprises a piercing probe configured to pierce insulation of the at least one of the plurality of wires. 
     
     
         15 . The vehicle electrical system tester of  claim 1  including a user input coupled to the test circuitry. 
     
     
         16 . The vehicle electrical system tester of  claim 15  when the user input is configured to receive information related to a gauge of the at least one of the plurality of wires. 
     
     
         17 . The vehicle electrical system tester of  claim 1  wherein the test circuitry provides an output in the form of “voltage drop at XX amps”. 
     
     
         18 . The vehicle electrical system tester of  claim 1  wherein the test circuitry provides an output related to electrical parameter of the at least one of the plurality of wires and a scaling factor. 
     
     
         19 . The vehicle electrical system tester of  claim 1  wherein the electrical parameter of the at least one of the plurality of wires comprises a dynamic parameter 
     
     
         20 . A method of testing wiring of an electrical system of a vehicle, the wiring including a wiring harness which extends between electrical components of the vehicle, the wiring harness including a plurality of wires, the method comprising:
 coupling test circuitry to one end of at least one the plurality of wires in the wiring harness;   coupling the test circuitry to a second end of the at least one of the plurality of wires of the wiring harness;   applying a signal between the first and second ends of the at least one of the plurality of wires of the wiring harness; and   measuring a parameter of the at least one of the plurality of wires of the wiring harness using the test circuitry based upon the signal applied to the at least one of the plurality of wires of the wiring harness.   
     
     
         21 - 26 . (canceled)