Hitch / Wiring Installation Diy Info Here

[commspectra]

Hi, brand new to Lexus as I have driven Saabs for 20 years. But since the new Saab looks like a Trailblazer I bought a RX300! I need to tow a trailer and set out to research the options. After searching trough the posts concerning the subject here is what happen.

First let me say I have my degree in electronics and own my own company installing phone systems. I have installed hitches on my Saab's - so I am familiar with the process. But overall it's a pretty easy job for anyone with basic tools and skills. The wiring parts I used are the same parts local tow shops use.

I have a 2002 FWD RX300 with NO tow prep package listed on the original window sticker. After looking, I did have the tow wiring connector (where the factory brain/controller would plug in) by the spare tire and also the pigtail connector under the car in the box under the spare tire.

I purchased a very nice quality and good looking hitch from eTrailer.com - installation was very easy - took about 30 minutes total. (#70777) This hitch has the tube contruction which I think looks better than the square tube ones the local people carry.

I purchased a DrawTite ModuLite trailer light power module (#18146) and a Hoppy Mag Flat Bracket kit (#48085) both locally. The ModuLite you have to have. The Hoppy part is just the wiring and 4 wire connector that goes down to the trailer. It is nice because it is already wrapped and has a magnetic housing that keeps the connector out of the way. But you can use any 4 wire connector about 60" long.

Here is a rundown of what I found out about the wiring. As stated above, my car did not list the tow prep package but did have the connector by the spare tire (a white 10 pin - 9 wire- female rectagular brain/controller connector) and the 4 pin -4 wire- grey housing pigtail connector in the rectagular black box under the car under the spare tire, I did not use this connecter. This 4 pin connector is wired up to the 10 pin connector.

I tested the pins on the 10 pin connector (without the tow fuse in the fuse box under the hood) to find out which pin controlled what. Here is the breakdown-

Looking at the connector with the snap pin up. Looking at the connector the pins are shaped like a U. ::..::

The left side red 4 wires come from the pigtail under the car, these are not used in my installation. The 3rd pin over from the left on the bottom has no wire connected. The 4th wire over on the bottom is the Power that is hot when you put in the tow fuse (don't put the fuse in now). the 5th pin over from the left on the bottom is the Brake light, the 6th pin over from the left on the bottom is the Right turn signal - this is the last pin on the bottom row. Right above the right turn pin is the Left turn pin, this is the top row most right pin. To the left of that is the Running light pin.

The instructions with the ModuLite are very short. The RX uses the 3 wire system. The only thing different and a big disclaimer --- the instructions state to connect the black battery wire directly to the battery --- I chose to use the power on the connnector coming from the fuse box. You can make up your own mind on what you think is best. I figured this is how the factory brain would power the lights so I chose to use it. I did not feel like snaking a wire up to the battery.

Remove the spare tire. Follow the short ModuLite directions. The kit includes wire taps but you will need additional taps - both blue ones and a yellow 12 guage wire tap if you chose to use the connector power. Splice the ModuLite wires into the correct connector wires behind the 10 pin connecter using blue taps. . The black wire (if you choose) splices into the power wire using the 12 guage tap. Stagger the taps so the bundle does not get too big. I connected my ground wire to a bolt right on the ridge below the hinge of the spare tire cover. The Modulite unit comes with the trailer 4 wires and connector on it, but you would have to cut a big hole in the grommet to get through the body, so that's why I bought the seperate Hoppy tail/connector so I could just cut a slit in the grommet and feed the wires up through. Makes a nice tight seal. Splice the Hoppy wires onto the same color wires on the Modulite trailer side.

I had a little 3 dollar tester that plugs into the trailer connecter to test the installation. Put a 20 amp fuse in the spot labeled Tow in the fuse box under the hood. Plug the tester into the trailer connnector. Test the running, turn and brake lights. I taped and tie wrapped my wires and mounted the modulite with some double sided tape to secure everything.

Well I hope this helps someone as I was very confused on how to get this going. I thought I would have to buy the brain/controller from lexus, but this is how the local tow shops do it. Seems to work great and I saved alot of money! I have a picture that I hope gets attached. If not let me know I can send it to you.

[mikey00]

Interesting find that you have the connectors even though the towing prep package is not listed. However, once you have the connectors all you need is Lexus PowerConverter PN # 08921-48070 for $77. Just plug it in then plug in the pigtail underneath the car, put the fuse in and you are good to go. No wiring, just a quick plug in.

[commspectra]

I called around and the two local dealers would have to order the part. Cost $113. I paid $35 for my parts. But you are right with the power converter from lexus - very easy!

[mikey00]

I called around and the two local dealers would have to order the part. Cost $113. I paid $35 for my parts. But you are right with the power converter from lexus - very easy!

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Lexus converter is $77 from newlexusparts.com. Good luck with your hitch. I have the same one.

[commspectra]

Now I find the part cheap!! That's the way to go if you have the connectors there. Oh well I got to get to know my car a little better. Owning my Saab's ,over the years, you learn to work on your own car!!!!!!

[hatrost]

How easy was it to install the Hidden Hitch Class III, you said you did it in only 30 minutes, was there any drilling?

If it only took 30 minutes is it safe to assume all the holes lined up and you just scrwed it in?

did it come with instructions?

[mikey00]

How easy was it to install the Hidden Hitch Class III, you said you did it in only 30 minutes, was there any drilling?

If it only took 30 minutes is it safe to assume all the holes lined up and you just scrwed it in?

did it come with instructions?

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HiddenHitch #70777 is very easy to install and comes with directions. There are 2 brackets used as tie downs for shipping under the rear of the car on both sides. Remove these (2 bolts each) and the hitch bolts in to the existing holes. Total time about 30 minutes. You can download the installation instructions for the RX at etrailer.com