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Discussion Starter · #1 ·
I have the Coastal Etech towbar installed. Not going to do any serious trailering, of course, but occasionally I have the need to tow a lawn machine from the rental place to home. They have the 4 prong flat connector for taillights and turn signals, to make them legal.

What I need to know is if anyone has experience hooking up the connector to the Prius tail and brake lights. The kit I have includes a 'push through' connector, and instructions as to which wire goes where, but in a cursory inspection of the tail and stop lights through the access hole, I see MANY little colored wires. Anybody know which wires I should be hooking up to? Thanks.
 

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A simple cheap 12 volt radio shack test light, the kind with the needle point for passing through insulation should find you the correct wires in the left tail light as you work the light controls. This said I now pass on a warning given to me. With the advent of "air-bags", more are accidentally deployed by amateurs trying to wire up trailer hitch lights. I would find an outfit that sells trailers in your area and go pay a guy that does it for a living an hour of his time.
 

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Brake lights are light blue, right turn is green, left turn is yellow, tail lights are brown.

Ground is always white with black stripe.
 

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Discussion Starter · #4 ·
Thanks for the replies. Thought I'd share my experience with actually trying it. Taillights prove to be no problem- white wire to the ground bolt at the back of the car, brown wire to lower light.

Turn and stop lights, problem. First, since turn and stop lights are separate, and I didn't have an adaptor to 'mix down' to the four prong plug, I decided stop lights were more important. Attached the yellow and green wires as specified to the brake lights left and right. No joy.

Volt meter revealed that the voltage supplied to the stop lights is about 3-4 volts DC, rather than the 12 volts needed by the trailer lights. Makes sense, since the brake lights are LEDs. To get the setup working correctly would require some sort of relay that uses the 4v brake signal to trigger 12v to the trailer lights, and also deals with turn signals. Not competent to design such a thing myself. Sounds like a new product for Coastal ETech....

BTW, a friend tells me that he used his Prius and the Coastal ETech hitch to tow a 4x8' light trailer with a couch onboard, and it worked great, even at highway speeds. Knocked his mileage down to about 30, however. He couldn't get the stop/turn lights working either, so he just kept his lights on and hoped for the best!
 

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Yellow and green are turn signals, not stop lights. Re-read my post, brake is light blue.
All of it is 12V with reference to ground.

Brake circuit is as follows: from 7.5A stop fuse, goes to brake switch, from brake switch goes to all 3 LED brake lamps (left, center, right), from them to ground.
 

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Discussion Starter · #6 ·
Thanks for the detail. The yellow and green wires I referred to were from the 4-way trailer adaptor, not the Prius. I was hooking in to the wire feeding the stop lights themselves, since I'd have no idea where the brake light relay is located.
 

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Dan, in another thread it was implied that LEDs operate at 4-5 V, not 12 V. Is this incorrect, or is there a resistor in the lamp circuits or assemblies?
 

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As I stated before, from the power distribution, goes to 7.5A brake fuse, from brake fuse, to brake light switch, from brake light switch, to all 3 brake lamp assemblies.

Each of the 2 brake lamps have a series of LEDs, and a circuit to manage the internal current which is integral to the assembly. That blue wire is guaranteed 12V.
 

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Towing question...

Hello,

How much can the Prius tow? The dealer wouldnt give any info.I hear there is tow set up available? Anyone know how much it could safly tow?
I did not get this vehicle to tow but I was thinking of getting an aluminum boat with a 40 HP motor and the distance to tow would be less than 5 miles to put in for the season and take out in the fall.
Regards,Ed
 

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Get a friend with a tow hitch to help you get the boat into and out of the water. There is no tow option available. (heavy suspension, transmission cooler capacity increase, trailer wire pkg, ect:) The car "is what it is"
However, for what you are describing coastals or "U" haul it tow bar intallation sans lights should work out well.
 

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Re: Towing question...

edlambert said:
Hello,

How much can the Prius tow? The dealer wouldnt give any info.I hear there is tow set up available? Anyone know how much it could safly tow?
I did not get this vehicle to tow but I was thinking of getting an aluminum boat with a 40 HP motor and the distance to tow would be less than 5 miles to put in for the season and take out in the fall.
Regards,Ed

Towing is not recommended by Toyota. Your warranty can be voided by towing over the recommended amount, and since the recommendation is not to tow...

That hasn't stopped some people from towing small, lightweight trailers (say for a motorcycle) short distances/slow speeds.

Apparently in one of the small European countries (I don't remember if the Netherlands, Luxumburg, or some other country in that area), the 2004+ Prius can be purchased with a Toyota tow bar, though...
 

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OOps!

I should have said I reposted this after spending time finding it! I've been thinking of hooking into the tail lights of my Prius.But I was on Prius technicle instead of Q&A.

Sorry about that, Ed
 
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