How to Power Brakes on a Tow Dolly Being Towed By an RV

Question:

Hello eTrailer, We have a Newmar 2002 Dutch Star DP with a 7-pin trailer connector. Looking to buy a tow dolly with electric brakes. Does the 7-pin type connector style engage the brakes on the dolly automatically, when I apply the breaks on the coach? I do not see any switches or levers on the dash to manually engage the dolly breaks. Appreciate the advice! Much to learn re: the breaking system here.

asked by: Steve G

Expert Reply:

To power the tow dolly's brakes you will need to install an electric brake controller into the RV. It installs under the RV's dash. Some vehicles have a factory connector and a wiring harness can be purchased to make installation easier, others will need to be hardwired.

The controller I recommend is the Prodigy P3 # 90195. It's one of the most reliable controllers on the market plus has an easy to use LCD. I've linked a review video for you.

If there isn't a connector under your dash to install the P3, or any brake controller, you'll need to hardwire it in by running the black wire to the RV's battery, the white wire to a good ground location, the blue wire back to the RV's 7-way trailer connector, and the red wire to the cold side of the stop light switch in the motorhome's cab.

expert reply by: Charles S