I dropped the wire straight down from the battery and it runs to the rear passenger tail light above the flat bottom panels that cover the underside.
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Aftermarket Hitch Installation for Model 3
- Thread starter dhrivnak
- Start date
Caution do not try this at home.
I had my first real towing experience and leaned a few things. The Watts/mile towing our 2000 lb ALiner was up a hefty 66% or 382 Watts/mile versus our standard 230 Watts. So range would be more like 180 miles. The campground only had a 20 amp 110v outlet but after two nights we were at full charge again. On the way up (4000 ft) we used a hefty 450 Watts/mile but the way back home was down to 312 Watts.
Just for a test I stopped by the Pinnacles SuperCharger and they seem to have one that works when towing. BUT this would likely not work if the chargers were full.
The round trip was 180 miles with about 40 miles interstate 60 miles 2 lane 55 mph roads and about 80 miles winding mountain roads at about 40 mph. The camper and car did fine. But no navigation in remoter areas with no hope of cell coverage.
I had my first real towing experience and leaned a few things. The Watts/mile towing our 2000 lb ALiner was up a hefty 66% or 382 Watts/mile versus our standard 230 Watts. So range would be more like 180 miles. The campground only had a 20 amp 110v outlet but after two nights we were at full charge again. On the way up (4000 ft) we used a hefty 450 Watts/mile but the way back home was down to 312 Watts.
Just for a test I stopped by the Pinnacles SuperCharger and they seem to have one that works when towing. BUT this would likely not work if the chargers were full.
The round trip was 180 miles with about 40 miles interstate 60 miles 2 lane 55 mph roads and about 80 miles winding mountain roads at about 40 mph. The camper and car did fine. But no navigation in remoter areas with no hope of cell coverage.
xpitxbullx
Member
Did you exceed 55 mph on the interstate? Were your camper tires at max inflation? These will play a very large role in energy consumption, too.
How well did brake regen help in slowing down or stopping?
Your setup looks awesome!
On the Interstate I drove 65, below the speed limit but the limit of the camper and yes the tires were at the maximum 50 PSI. The regen works as expected but I likely lose a little as the trailer electrical brakes come on anytime the tail lights come on.
Yanquetino
Member
Thanks so much, but (as usual for me) I'm confused. "Above" the flat bottom panels? How did you get the wire "above" them? I see that the side rocker panels have a few access flaps, with screws inside them. Did you removed those screws, loosened the panel, strung the wire under it, and replaced the screws?
I want to install an EcoHitch, primarily for our bike rack, but also to tow a very light trailer (only 265 lbs., with a 17 lb. tongue weight). This is why I'm interested in how and where you wired the harness, as I've never tackled such a challenge before.
Mmmmaybe I shouldn't… "try this at home," as you say?
Yes those flaps underneath give access to the bolts that hold the bottom air shield. If you remove the bolts on one side you should have plenty of room to add a wire from the battery to the rear of the car.Thanks so much, but (as usual for me) I'm confused. "Above" the flat bottom panels? How did you get the wire "above" them? I see that the side rocker panels have a few access flaps, with screws inside them. Did you removed those screws, loosened the panel, strung the wire under it, and replaced the screws?
I want to install an EcoHitch, primarily for our bike rack, but also to tow a very light trailer (only 265 lbs., with a 17 lb. tongue weight). This is why I'm interested in how and where you wired the harness, as I've never tackled such a challenge before.
Mmmmaybe I shouldn't… "try this at home," as you say?
Yanquetino
Member
Aha…! Mystery solved. Thanks so much! And the wiring harness from eTrailer was fairly easy to install? Any advice or tips that the instructions don't cover? Other than the bolts mixup, were there other difficulties installing the EcoHitch?
Yes I used the passenger rear for the module and for wire access. The hitch instructions showed how to remove the rear panels which are easy. I think three of the pop connectors.
xpitxbullx
Member
This is why I'm interested in how and where you wired the harness, as I've never tackled such a challenge before.
Mmmmaybe I shouldn't… "try this at home," as you say?
I’ve wired a 4 prong harness to the brake lights. It worked with regular bulbs but I’ve since swapped the trailer lights with LEDs.
Here is the info you might need. I can verify there is no problem or conflict with the computer. Cost for plugs connectors and wire harness under $25.
I wired the harness behind the tail light plugs. 3 wires on one side and 1 on the other. Tesla Model 3 tail lights are 12v. Perfect. I used red quick splice connectors (22g-16g).
Slot 1 - ground (18g wire)
Slot 2 - running lights (22g wire)
Slot 3 - brake/turn indicator (22g wire)
Slot 4 - empty
Slot 5 - reverse (not needed for harness)
Hope that helps.
israndy
Supercharger Hunter
Anyone thinking about doing the 7-pin connector on the back? All my other vehicles have that on them. Will be interesting to see if I can tow my Insight. It's less than 1800 lbs.
-Randy
-Randy
xpitxbullx
Member
I can come up with the 7-pin method if it’s necessary. Is this what you plan to do?
Unless you are charging an aux 12v on the trailer, you can just do a 7pin to 4-pin adapter and it will still activate the trailer brakes.
Xenoilphobe
Well-Known Member
xpitxbullx
Member
xpitxbullx
Member
I love posi-locks and positive-taps. I wouldn’t use taps on this job. Locks, yes. Taps, no. 22 gauge wiring is smaller than I care to tap.
Yanquetino
Member
If I may, I'd like to ask a few more questions about wiring the harness. Since you "used the passenger rear for the module and for wire access"...
* I assume you ran the wire from the battery down that side of the vehicle under the air shield, correct? If there a reason you opted to use the passenger side, rather than the driver side?
* Where and how did you secure the module on that side? Just set it behind the rear panel covering those tail light wires? Tie, tape, or screw it down inside that area?
* Where and how did you secure the ground wire? Did you use the supplied self-tapping screw to connect it to the body? Where?
I really appreciate you being the pioneer (guinea pig?) for such projects, and answering the questions of us novices!
Xenoilphobe
Well-Known Member
If you pull the front wheel liner, their is a large conduit the runs the length of the car....just fish the wire through there... this is what it looks like on the S... I then just drilled a hole from the cabin straight down into this conduit, just pull up the door threshold and I drilled through...
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I actually ran it down the driver's side, but if I were to do it again I would attempt to use the passenger as I think that would save a little wire, but in reality probably makes little difference. Just make sure you put the fuse next to the battery connection.
For securing the module it had a screw hole and I found a ground wire and screw in there that I think is used by the amp. So I used that same screw to mount the module and the ground wire I do believe. The module is small and weighs an oz or two. So not much needed to secure it. If you look below the light down toward the ground you will see some air vents that you can run the wire to the bottom side. I think I removed the screws/plugs for the passenger wheel liner where I had more space to help route the wire.
If you are really struggling I may be able to snap a few pictures tomorrow. I did not document as I am not sure it is the best way. It worked but I have only done 4 hitches in my life and 3 wiring kits, this was the first one with LED lights and the inductive pick ups so I was mostly feeling my way through.
Yanquetino
Member
That's all very helpful! I am still waiting for the harness to be delivered, but today I pulled back the felt over the passenger tail light section to see what was in there. It does look like it has much more room to accommodate and connect the components than on the driver side. I am now much more confident that I can tackle this challenge. Thank you for answering my questions!
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