Prodigy P3 Trailer Brake Controller Installation in 2008 Lexus RX 400h with 4-Pole Wiring

Updated 08/02/2017 | Published 07/31/2017

Products Featured in This Question

Tekonsha Prodigy P3 Trailer Brake Controller - 1 to 4 Axles - Proportional

(6643)

$155.20

Equal-i-zer Weight Distribution System w/ 4-Point Sway Control - 6,000 lbs GTW, 600 lbs TW

(840)

$825.00

Universal Installation Kit for Trailer Brake Controller - 7-Way RV and 4-Way Flat - 10 Gauge Wires

(3397)

$121.19

Question:

Hello, HELP !!! Our family SUV is equipped properly for us to tow up to 3,500# dry weight. We only have a factory installed flat 4 pin connector which has been fine for a small boat, but now we are getting a small hybrid travel trailer with dry weight of 2,700# and has two wheels each side with their own brakes. We need a 7 pin connector to hookup to the travel trailer which has one already. The Lexus dealer has been no help. The typical camping trailer businesses have been too busy to deal with us since we are buying a camper privately. Any suggestions as to proper parts and where else we could look to have them put on properly? Thank you.

asked by: Warren &

Expert Reply:

I can help you with getting your 2008 Lexus RX 400h that already has 4-pole wiring equipped with a trailer brake controller and 7-way wiring setup to allow you to tow your new travel trailer that has electric brakes.

Since you already have 4-pole wiring in place all you need is the trailer brake controller itself and the installation kit # ETBC7. No other parts are required.

I recommend the user-friendly and very reliable Prodigy P3 # 90195. This unit has a fantastic performance record and includes features that make using it easier, such as storable settings and a nice clear display. You can see what thousands of satisfied customers have to say about it by reading the many glowing reviews on our site.

The # ETBC7 kit includes all the wiring components needed to install the controller and to have a 7-way trailer connector on the RX 400h. A detailed installation guide is linked for you.

The Prodigy trailer brake controller will help you stop the new trailer but since the loaded trailer will be very close to the curb weight of the RX 400h (which ranges from 3870 to 4365-lbs depending on equipment) you will need a weight distribution/sway control (WD/SC) system to keep the trailer steady when it is hit by wind gusts and air blasts from passing trucks. You can refer to the linked article and video on WD systems for more on what they can do to reduce your white-knuckle moments on the road and to maintain your steering and braking performance.

You will want to choose a WD/SC system based on the trailer's loaded tongue weight (TW). This can be easily measured with a scale # e99044. You also want to count the weight of any cargo in the car behind the rear axle, say a generator or loaded cooler, since this will act like trailer TW. What you want to do is load up the trailer as you will for a trip, with water and propane tanks full, and your supplies and gear in place, and then measure the TW. WD system need to be tuned to the actual TW of the towing setup. All such systems work over a range of TW; you want your total TW to fall near the middle of the system's operating range.

If the camper's dry weight is 2700-lbs, we'll figure that when loaded up it will be closer to 3500-lbs. based on the usual TW formula for a properly-loaded trailer, your TW should be about 12% of the trailer's gross weight. Based on a gross weight of 3500-lbs your TW is likely to be 400 to 500-lbs.

I linked our main page for WD/SC systems that will work with your trailer. If you select the 500-lb TW you will see systems like the Equal-I-zer # EQ37060ET which would be ideal for a trailer TW of 400- to 500-lbs. This will both shift trailer weight forward on the Lexus' front axle (to keep your steering and braking performance intact) and also prevent trailer sway from passing vehicles.