Troubleshooting Tekonsha Wiring Harness With Only 10v Output

Updated 12/11/2024 | Published 12/10/2024

Question:

I recently installed your Tekonsha trailer hitch wiring system on my 2022 Audi q5. All went well but the module output is only 10 volts rather than 12. Is this to be expected or is something amiss? Thanks,

asked by: John B

Expert Reply:

Hey John, thanks for reaching out. There are a few things to check here. First will be to check that your ground is attached to a clean and corrosion free bare metal surface. No paint or undercoating either. Also, it works best if it is grounded by itself and not with other items. A bad ground is by far the most common cause of wiring harness issues. Also make sure the black wire is run directly to the battery and not to an alternative power source. The output should be at least 12v but could read as much as 14v.

If that does not help, the next step will be to test the converter. In this case you will want to test the input wire and make sure you are getting 12v input. If the input is normal, but the output is wrong, this means the converter module is bad and will need to be replaced. It is pretty rare for a converter to be bad right out of the gate, but it is not entirely unheard of. Check that input and that will tell us the next steps.

expert reply by: Jesse M

John B.

12/11/2024

Jesse, I must have been a little off on my previous measurement. I now get 12.4 volts into the module and 11.8 volts out. Is this normal? Thanks, John