Switching An Electric Over Hydraulic Brake Set Up To Surge Brakes  

Question:

Expert Reply:

Hi Scott!

You can do either! The brake controller option would be the way I would go though as you wouldn't have to bleed the brakes (which is a pain in the butt) and it can be used with other trailers that have electric or electric over hydraulic brakes (plus it works better than surge brakes). For that, you will only need a few things, but I wanted to ask a few things first. Are you sure it's a 6-pin plug? They aren't used very often, but will still work. I included a picture showing the difference. If it is indeed a 6-pin, you will need the following parts for your 2009 Toyota Sienna:

Tekonsha Prodigy P3 Trailer Brake Controller - 1 to 4 Axles - Proportional # 90195
Tekonsha T-One Vehicle Wiring Harness with 4-Pole Flat Trailer Connector # 118304
Universal Installation Kit for Trailer Brake Controller - 6-Way and 4-Way Flat - 10 Gauge Wires # ETBC6

I included a 4-flat as you will need one for the brake controller wiring kit to piggyback off of. If you already have one on your Sienna, you can leave that part off.

If it turns out to be a 7-pin on your boat trailer, you will want the following parts (I included the 4-flat again, but as before, it can be left off if you have one already):

Tekonsha Prodigy P3 Trailer Brake Controller - 1 to 4 Axles - Proportional # 90195
Tekonsha T-One Vehicle Wiring Harness with 4-Pole Flat Trailer Connector # 118304
Universal Installation Kit for Trailer Brake Controller - 7-Way RV and 4-Way Flat - 10 Gauge Wires # ETBC7

If you wanted to change the 6-pin on your trailer to a 7-pin (which is a much more common style), I would grab the Trailer Wiring 7-Way Upgrade Kit w/ Junction Box and RV Style Connector # e99011 to make the swap. It makes wiring a lot easier.

The Tekonsha Prodigy P3 brake controller # 90195 is the best one on the market for electric over hydraulic set ups, and I highly recommend it. It's also easy to use and set up.

To go with a surge brake set up, you can use the Dexter DX7.5L A-60 Brake Actuator w Electric Lockout - Bolt On - Disc - 2" Ball - Zinc - 7.5K # DX89FR you were looking at. I am not sure if your current actuator is welded or bolted on, but it will need to be removed either way. The electric lockout is actuated by the reverse lights on your Sienna, so you would still need to do a little wiring. I have the components for that listed below. I included a junction box as it will make it easier, but also the 4-flat, which can again be left out if you already have one.

Trailer Wiring Junction Box - 7 Terminal # e99009
Adapter 4 Pole to 6-Pole and 4 Pole # 37175
Adapter 4-Pole to 7-Pole and 4-Pole # 37185

The adapters will depend on the trailer plug and will piggyback off the 4-flat, just as before. You will end up with an empty post in the junction box, but that's perfectly fine.

I know this is a long response with a lot of parts and information, so just let me know if you have any questions or need clarification on anything.

Out of curiosity, what kind of boat do you have?

expert reply by: Lazer S

0

6 And 7 Pin Comparison
(click to enlarge)

ETBC7 Wiring Diagram
(click to enlarge)

Lazer S.

9/12/2025

Hey Scott, Did you have a chance to check the plug on your trailer to see if it's a 6-pin or 7-pin? I'm eager to hear how your setup is coming along and if the information I provided helped you decide on the best solution for your trailer. Let me know if you need any more assistance!

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