How to isolate one circuit from the system to get an accurate reading. Wire the vehicle side wiring harness to a standalone battery.
How To Use Multimeter Tutorial 14 Youtube Multimeter
Checking trailer wiring with a multimeter. You an use the wiring diagrams i have linked for you. You will need to have someone sit in the truck and run through each function while you test the pins. The most critical aspect of connecting trailer lights is wiring the system up and for your the lights to function rightly you should get the proper cables. Many trailer connector wires come with the controls branded on the wire but if yours is not labeled you need to know the right wire arrangement. Replacement light bulbs optional sandpaper optional electrical contact cleaner optional the configuration of the 7 pin trailer plug. Hook up your trailer and connect the trailer light harness.
If all the lights appear dim or you have no lights at all check the trailer light harness at the tow vehicle. The 7 pin trailer plug is complicated because it hosts 7 different connections all in one watch the video right below this paragraph. You dont know if the wiring is bad or you have bad bulbs. All you have to do is link up the white wire to the negative and the colored wires to the positive. I have attached a photo of the btmt15 and have noted where the test position is. Have a helper stand back to see if the running lights stoplights and blinkers are working properly.
One way to troubleshoot the voltage on the connector plug is to use a circuit tester. Check your vehicles plug configuration. Determine if the issue is with the tow vehicle wiring or trailer wiring. This will take the reading for a system that has 0 to 20 volts. If you are wanting to use a multimeter to test the 12 volt system on your vehicle when you are installing the curt t connector wiring harness part c56165 you would set the multimeter like part btmt15 to 20 on the dc side. Test trailer wiring harness multimeter see part checking lighting system with an ohm meter.
On a four prong plug one prong connects to the right turn signal one to the left and one to the tail lights. How to connect trailer lights. Youve connected the trailer to the vehicle but the turn signals and brake lights dont work. Two types of a trailer wiring tester. 2 people one to run the vehicle and one to run the multimeter. While checking the connectors if you notice any corrosion build up or dirt inside or or in back of either connector clean it out.
Disconnect the trailer from the vehicle and run a test to determine if the trailer lights function properly. In order to determine the configuration on the trailer side you will have to trace the wiring back from each pin.
Gallery of Checking Trailer Wiring With A Multimeter
