You have no items in your shopping cart.

Test procedure when your Tow-Pro is flashing red

How to test the earth wiring when your Tow-Pro is flashing red


If you’ve read why there is a flashing red fault code on your Tow-Pro Elite, you should now be ready to test the earth wire connections.


Testing should be done with the trailer wiring plug plugged into the vehicle’s trailer lighting socket but with the trailer not coupled to the vehicle.


Switch on all circuits of trailer lighting and ensure that any trailer battery is being charged via its Anderson plug.


If the Tow-Pro™ LED is flashing red, unplug the battery charging Anderson plug. If the LED stops flashing red, check for a poor connection or undersized earth wire from trailer battery negative via Anderson plug to vehicle chassis. If it is still flashing red, measure the voltage drop from trailer earth to the point where the vehicle trailer socket (Pin3) is earthed to the vehicle, then from earth point to start battery earth. If a total of more than 0.4V is found, take the below steps to reduce the total voltage drop as much as practicable.



Test procedure red flashing tow-pro



Download this tech tip as a PDF or for further assistance and technical support contact REDARC directly.

Afterpay. Shop now. Pay later.

All you need to apply is to have a debit or credit card, to be over 18 years of age, and to be a resident of Australia.

Late fees and additional eligibility criteria apply. The first payment may be due at the time of purchase. For complete terms visit