Lack of Voltage From 4-Way Trailer Connector on 1999 Toyota RAV4

Question:

Just installed the hitch and also the T - wiring harness I am only getting about 4 volts dc out of the 4 way connector. what voltage level should I get? I was expecting about 12 what could be the problem?

asked by: Milan L

Helpful Expert Reply:

The issue you are having with the lack of voltage from your 4-way connector on your 1999 Toyota RAV4 could be the result of a bad ground.

Start your troubleshooting by checking the connectors for dirt or corrosion. Next, you will want to check the ground on the vehicle-side connector. It should be attached to a clean bare metal surface on the vehicle frame. Then check the trailer-side main ground. It should also be attached to a clean bare metal surface on the trailer frame.

You may also need to check the converter box. You will use a circuit tester such as the # PTW2993 with the power off. Check the signals going into the box first, then the signals coming out. If the signals are not right going in, there is an issue with the vehicles wiring. However, if they are correct going in, test the signals coming out. If the issue is with the signal coming out, you will need to replace the converter.

I have added a link to a video on Modulite troubleshooting that could help you. You should be getting approximately 12 volts on the 4-way side of the converter.

Once you have done that, if there is still a problem, check the physical condition of the wiring by looking for any breaks or nicks and repair as needed. Using the # PTW2993, you can check the entire length of the wire to locate the breaks you cannot see. If you have determined that the power is not making it to the trailer, you can use the circuit tester on the vehicle side as well.

I have included links to some videos that should further help you determine the potential issue with your wiring. If you find this does not solve your problem, please let me know and I will provide further research.