R500 AND TOWING
Junior Member
Joined: Nov 2010
Posts: 5
I got the hitch on, it was a bear to get the holes to line up. I mounted both bumper bolts (as loose as possible), but the trunk pan bolts still wouldn't line up. They were at least 3mm off, and go in at a slight inward angle. I had to remove the left bumper bolt, then install the trunk pan bolts, and then reinstall the left bumper bolt after forcing the hitch into position using a 6' 4"x4" and my Son. What a pain! I cut a 9" wide x 1.75" deep section out of the bumper cover using my dremel w/ cutting wheel, and removed a good sized section out of the trunk pan cover.
Thanks for the instructions and pictures.
I received the light modulator yesterday, and bought the wiring accessories listed above. I plan to install it this weekend, though I don't initially need lights (main purpose of hitch is a bike rack), so this could get bumped for other honey-dos.
Thanks for the instructions and pictures.
I received the light modulator yesterday, and bought the wiring accessories listed above. I plan to install it this weekend, though I don't initially need lights (main purpose of hitch is a bike rack), so this could get bumped for other honey-dos.
Junior Member
Joined: Jun 2009
Posts: 10
Ah, memories...
I too remember the sweating and the cursing. My son was only 5 at the time...so I had no help. I ended up putting the bolts in at slight angles and cranking them half turns in a circle so that they would all eventually line up. I REALLY wish they would make those holes just 1mm wider a piece. That would solve the entire problem.
The wiring, of course, is much easier. Bravo. Good job!
I too remember the sweating and the cursing. My son was only 5 at the time...so I had no help. I ended up putting the bolts in at slight angles and cranking them half turns in a circle so that they would all eventually line up. I REALLY wish they would make those holes just 1mm wider a piece. That would solve the entire problem.
The wiring, of course, is much easier. Bravo. Good job!
Junior Member
Joined: Nov 2010
Posts: 5
I bought one of these (link below), and hope to install it this weekend. Like you, I don't really need lights right away, but we sometimes rent small utility trailers, and would like to be prepared.
http://www.etrailer.com/Custom-Fit-V...cleid=20077345
A modulator is required to interpret the signals from the duplex wiring, and is wired to the 12v system to provide it's own power, preventing voltage fluctuations in the turn signal and brake circuits (which the vehicle might detect, and raise errors).
http://www.etrailer.com/Custom-Fit-V...cleid=20077345
A modulator is required to interpret the signals from the duplex wiring, and is wired to the 12v system to provide it's own power, preventing voltage fluctuations in the turn signal and brake circuits (which the vehicle might detect, and raise errors).
Junior Member
Joined: Oct 2011
Posts: 2
Hitch and Wiring
..
Wiring:
1. Remove the spare tire and vanity panels on both sides.
2. Use the double-stick tape on the back to mount the wiring adapter on the shelf to the left of the spare tire with the 4-prong trailer plug facing away from you. You can also use an M6 bolt to mount it to the many M6 tabs sticking out all over the shelf. I used both.
3. Open the wiring installation kit and crimp the yellow eyelet to one end of the fuse holder (cut the loop to do this).
4. Using the M8 bolt, mount the eyelet to the bottom bolt of the rear fuse box (this bolt actually feeds 12v constant to the rear of the car). Do NOT insert the fuse yet.
5. Using the yellow butt-connectors in the installation kit, connect half meter length of power wire (provided in the kit) to the other end of the fuse holder and crimp the other end to the power lead of the adapter. Tuck the wire under the vanity panel covering the rear air-conditioning tubes.
6. Twist the brown and white wires of the adapter together (tail light and ground), use the 18 gauge eyelet to ground it to the floor pan with the M5 bolt. There are many of these M5 stubs around as well.
7. The wires on the adapter to crimp to your light harness wires are too short. You will need to extend them to get to your light harnesses. 10cm should do it. Use the butt connectors to extend all but the green wire (it is long enough to reach to the right side of the car).
8. Remove the left and right panels that access your rear wiring harnesses. Unplug them both.
9. On both harnesses, there is an orange wire. This is the ground. You don't need this wire, but use it as a reference. The wire next to it is the turn signal wire for either side. The wire farthest away is the stop light wire.
10. Use the quick splice connectors to splice into the turn signal wire and stop light wire on the left, the turn signal wire on the right. You will need to cut away some of the cloth wrapping on the harness to get enough space to do this. These connectors seem too big, but they are small enough to splice the wire.
11. Connect the relevant wires to the quick splice connectors using the plugs provided. Run the green wire across the car, tuck it under the vanity panel you tucked the power wire under, and connect it to the quick splice connector on the right harness. Plug the light harnesses back into the tail lights.
12. At this point, you are ready to test. There is a LED testing plug that comes with the kit. Plug this onto the trailer end plug (has 3 LED lights). Put the fuse into the fuse holder (you will hear a slight click when you do this, as the adapter powers up...make sure fuse does not burn out and is intact), put the key in the car and flick the turn signal lever. You should see the relevant lights flashing on the LED tester. If this does not work, crimp the connectors harder (may not have spliced well).
13. You can route the trailer plug through a rubber grommet on the left of the car that is visible. This grommet is used to wire the rear motion sensors for the rear bumper. There is plenty of space to cut it and feed the plug through it (you need to remove it first, and be careful not to harm the rear sensor wires if you have them). I did not bother. I just drape it over the rear sill and close the gate on it.
14. Put all of the panels and vanity covers back on and you are done!!!
!
Wiring:
1. Remove the spare tire and vanity panels on both sides.
2. Use the double-stick tape on the back to mount the wiring adapter on the shelf to the left of the spare tire with the 4-prong trailer plug facing away from you. You can also use an M6 bolt to mount it to the many M6 tabs sticking out all over the shelf. I used both.
3. Open the wiring installation kit and crimp the yellow eyelet to one end of the fuse holder (cut the loop to do this).
4. Using the M8 bolt, mount the eyelet to the bottom bolt of the rear fuse box (this bolt actually feeds 12v constant to the rear of the car). Do NOT insert the fuse yet.
5. Using the yellow butt-connectors in the installation kit, connect half meter length of power wire (provided in the kit) to the other end of the fuse holder and crimp the other end to the power lead of the adapter. Tuck the wire under the vanity panel covering the rear air-conditioning tubes.
6. Twist the brown and white wires of the adapter together (tail light and ground), use the 18 gauge eyelet to ground it to the floor pan with the M5 bolt. There are many of these M5 stubs around as well.
7. The wires on the adapter to crimp to your light harness wires are too short. You will need to extend them to get to your light harnesses. 10cm should do it. Use the butt connectors to extend all but the green wire (it is long enough to reach to the right side of the car).
8. Remove the left and right panels that access your rear wiring harnesses. Unplug them both.
9. On both harnesses, there is an orange wire. This is the ground. You don't need this wire, but use it as a reference. The wire next to it is the turn signal wire for either side. The wire farthest away is the stop light wire.
10. Use the quick splice connectors to splice into the turn signal wire and stop light wire on the left, the turn signal wire on the right. You will need to cut away some of the cloth wrapping on the harness to get enough space to do this. These connectors seem too big, but they are small enough to splice the wire.
11. Connect the relevant wires to the quick splice connectors using the plugs provided. Run the green wire across the car, tuck it under the vanity panel you tucked the power wire under, and connect it to the quick splice connector on the right harness. Plug the light harnesses back into the tail lights.
12. At this point, you are ready to test. There is a LED testing plug that comes with the kit. Plug this onto the trailer end plug (has 3 LED lights). Put the fuse into the fuse holder (you will hear a slight click when you do this, as the adapter powers up...make sure fuse does not burn out and is intact), put the key in the car and flick the turn signal lever. You should see the relevant lights flashing on the LED tester. If this does not work, crimp the connectors harder (may not have spliced well).
13. You can route the trailer plug through a rubber grommet on the left of the car that is visible. This grommet is used to wire the rear motion sensors for the rear bumper. There is plenty of space to cut it and feed the plug through it (you need to remove it first, and be careful not to harm the rear sensor wires if you have them). I did not bother. I just drape it over the rear sill and close the gate on it.
14. Put all of the panels and vanity covers back on and you are done!!!
!
Junior Member
Joined: Nov 2011
Posts: 2
Hi everyone, I am a new owner of an R350 and have been reading and searching the forums for the passed couple of weeks. Thank you for all the information and experiences shared.
I will be installing a hitch soon, but have a question.
From the picture, it looks like the ball mount (slider) is at a steep angle downward. It might be the picture angle. Can someone post a picture of the finished product with a slider/ball mounted?
Thanks!
I will be installing a hitch soon, but have a question.
From the picture, it looks like the ball mount (slider) is at a steep angle downward. It might be the picture angle. Can someone post a picture of the finished product with a slider/ball mounted?
Thanks!
Junior Member
Joined: Jun 2009
Posts: 10
It's realty hard to get a picture that is level, as you have to almost lay down to get an upwards shot. It does not slope down. It is low, but clears my super steep driveway no problem (I just need to slow down before I hit the slope).