Tow hitch wiring harness for Dummies - (Me)

Hello all. So I decided to finally install the tow hitch wiring harness for the tow hitch on the Mach. Although I installed a tow hitch mainly for a bike rack, I wanted to maximize the versatility (utility if you will ) of my Mach. I did do a search on here to get some of the Ps and Qs of the installation (along w/some YouTubing) and felt comfortable enough to do this project. Most of the instructions here are pretty straightforward, however, I found that information was scattered throughout threads so wanted to give my experience to the forum in a summarized version with some of my takes. So here goes...

First, I want to list all the products out front, so you don't need to scan through the whole post for this info:

1. Tekonsha Wiring Harness: TEKONSHA - Model 118840
2. Draw-Tite Wiring Harness: Draw-Tite - Model 118840
3. (Both wiring harnesses above are the same. Wanted to point out that they may be under different brand names. Just make sure to look for this model number: 118840
4. Curt Wiring Harness Bracket: Curt 4-pin bracket - Amazon
5. Wire Harness tester: Hopkins 4-pin tester - O'Reilly Auto Parts
6. Ramps: Black Widow Plastic Car Service Ramps - Amazon

Next, here is the video I used for reference:

And here is the Stealth Hitches instructions I also used as a reference:

• Stealth Hitch Mustang Mach E Installation Instructions PDF

The reason I have both these sources as references is because of how they run the power cable from the hitch to the 12-Volt battery. The U-Haul video has the cable running through the HVB support rail channel while the Stealth Hitch instructions has the cable going through the lower side trim next to the support rail. Personally, I went with the Stealth Hitch method. If that HVB ever needs to get dropped, that power cable is toast. Granted, if your HVB is getting dropped, you probably have bigger problems than a tow hitch wiring harness power cable, but still, give the little guy a chance .

Note: You can also run the power from the 12-volt outlet in the trunk. Probably a lot easier, I just didn't feel comfortable enough digging around for that so just ran to the battery.

TIP: I used this Klein Tools fishing tape. It's the kind you use for running cables/wires through walls for home theater installations. I ran this down that lower trim channel and took about 10 seconds to get the power cable through. The Stealth Hitch instructions has you taking out all the plastic fasteners. Not necessary, just the one at each end of the channel is all you need:



As for the install:

• This is definitely doable by one person. However, it is obviously easier with a helper. I specifically needed help guiding the Mach up the ramps. I did not trust myself doing that on my own, especially in reverse haha. Also, fishing the power cable up from the wheel-well area into the frunk would've taken excruciatingly long alone:

• The taillights came off surprisingly easy. Was afraid I might damage those, but no issues. Like the guy in the U-Haul video says, pull it straight out:

• You do have to drop the dirt skirt under the rear of the Mach. I highly recommend wearing a mask. It's like a dust storm under there when you take it off and put it back on:

• And unfortunately, if you run the power cable to the front 12-volt battery, all the frunk stuff has to be removed. It's really not that bad. The good part is, if you drop a clip, once the tub is out, you'll be able to retrieve it. The wiring here goes exactly as the U-Haul video. Forgot to take pics, but looked the same:

• Finally, the wiring in the back is really almost frame-by-frame to what the U-Haul video illustrates. The only thing I would add here is, you gotta really think about the placement of the harness plug bracket (unless you're going to stick it up into the bumper somehow and pull out when needed). I did not want to stick it in the bumper and attached the bracket. Please note, you WILL need to drill two holes in the bumper . I know, terrible. However, if you've cut a swathe of bumper already to get the hitch installed, what's another couple of 1/8" holes? haha. Here's my placement, and I'm not sure if I put it in the right spot. The U-Haul video guy has it in a slightly different location. If I relocate the bracket, no one will ever know there are a couple of tiny holes in the bumper, but that's me. Just to reiterate, really give the bracket placement some thought:

So good luck! Hope this was helpful,

orr

Nice work! Considering this on mine

Last I read in the owners manual


PRECAUTIONS


WARNING: Your vehicle is


not approved for trailer towing.


Never tow a trailer with your


vehicle.

Weather the body can withstand the load or not, or it’s the electronics. The electronics in an EV are programmed for the vehicle. Certainly EVS like the Ford Lighting have programming to accommodate trailers.

MachhE-CT said:

Last I read in the owners manual


PRECAUTIONS


WARNING: Your vehicle is


not approved for trailer towing.


Never tow a trailer with your


vehicle.

Weather the body can withstand the load or not, or it’s the electronics. The electronics in an EV are programmed for the vehicle. Certainly EVS like the Ford Lighting have programming to accommodate trailers.

Click to expand...

This has been discussed in many threads. The (same) car is approved to tow in Europe. The difference is that in Europe, trailer towing speed is limited so you can’t exceed the capabilities of the cooling system. If I had a use case to tow with my Mach-E (I don’t), I would do it, taking into account the limitations imposed by European regulations.

Problem is if it's not certified to tow and you get into an accident while towing your insurance company may not cover you and you may be liable for more than your think.

Star Lord said:

Problem is if it's not certified to tow and you get into an accident while towing your insurance company may not cover you and you may be liable for more than your think.

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I'll roll those dice, thanks.

Nice write-up Orr. I installed a Drawtite Hidden Hitch on my 21 GTPE and it went mostly as you described. The only thing I did differently is that I did not mount that last connector bracket. Instead I cut a little hole through the rubber plug underneath the carpet under the cargo area and just leave the cable tucked underneath the cargo mat with all the other accessories on the inside of the vehicle. Sealed up the rubber plug with Lexel top and bottom and good to go. This keeps the connector clean and avoids drilling any holes in the bumper or elsewhere and looks cleaner from the outside. To use the connector, just pull the cable out from under the cargo mat and close the rear hatch on it after it's connected.
I made a bike rack/platform with taillights for my wife's e-tricycle that will hold a total of 3 bikes. With all 3 bikes onboard, the taillights are almost completely obscured.

GT-Papa said:

Nice write-up Orr. I installed a Drawtite Hidden Hitch on my 21 GTPE and it went mostly as you described. The only thing I did differently is that I did not mount that last connector bracket. Instead I cut a little hole through the rubber plug underneath the carpet under the cargo area and just leave the cable tucked underneath the cargo mat with all the other accessories on the inside of the vehicle. Sealed up the rubber plug with Lexel top and bottom and good to go. This keeps the connector clean and avoids drilling any holes in the bumper or elsewhere and looks cleaner from the outside. To use the connector, just pull the cable out from under the cargo mat and close the rear hatch on it after it's connected.
I made a bike rack/platform with taillights for my wife's e-tricycle that will hold a total of 3 bikes. With all 3 bikes onboard, the taillights are almost completely obscured.

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Hey, where were you yesterday when I was doing this? lol ?

Yeah, I know, I briefly thought about hiding the plug up in the bumper area as well. That's why I mentioned it in the write-up as an option. But in the end, I didn't really care about drilling a couple of holes in the bumper, so I went w/the exposed bracket.

Your idea sounds pretty cool though. Maybe if you get a chance, you could include pictures of this mod and make it a supplemental variation to this install thread. I'm sure lots of people that come across this post will look for non-bumper drilling options.

orr,
Thanks for the detailed install notes. I installed the same EcoHitch and Tekonsha harness for a bike rack and local light yard waste hauling. https://www.macheforum.com/site/thr...how-did-you-wire-the-lights.41352/post-889729

For others interested in installing: I bought that 4-Way Flat plug bracket but returned it when I realized it was easier (and more aerodynamic ? ) to stick the plug to the back of the hitch with heavy duty velcro. I put the velcro on the ribbon cable just above the plug.

Also routing to and tapping into the hatch 12v accessory plug was pretty easy. I think it was easier than routing all the way to the LVB. Here is Mark Boris' post on opening the side panel to access the plug: https://www.macheforum.com/site/thr...bwoofer-w-amp-to-your-mach-e.5481/post-424030 . Only the rear clips need to be removed.

The yellow then black wire is the 12V tap routing. The black wire goes up through the tail light area and follows the tail light connector back to the Tekonsha assembly. I realize the 12V fuse is a bit out of the way to access but if I short it and it blows, it's my own fault and I'll deal with it. My bike rack and trailer lights are all LEDs.


This is the velcroed 4-Way Flat plug. It can be pulled out or just left there when in use. s
Also a note on the EcoHitch install. Only the two side cuts on the bumper and on the dirt shield are needed. Don't make a third cut across. Just bend the bumper and shield back as needed. This allows you to trim the side cuts to closely fit the receiver.

SteveMach-ee said:

orr,
Thanks for the detailed install notes. I installed the same EcoHitch and Tekonsha harness for a bike rack and local light yard waste hauling. https://www.macheforum.com/site/thr...how-did-you-wire-the-lights.41352/post-889729

For others interested in installing: I bought that 4-Way Flat plug bracket but returned it when I realized it was easier (and more aerodynamic ? ) to stick the plug to the back of the hitch with heavy duty velcro. I put the velcro on the ribbon cable just above the plug.

Also routing to and tapping into the hatch 12v accessory plug was pretty easy. I think it was easier than routing all the way to the LVB. Here is Mark Boris' post on opening the side panel to access the plug: https://www.macheforum.com/site/thr...bwoofer-w-amp-to-your-mach-e.5481/post-424030 . Only the rear clips need to be removed.

The yellow then black wire is the 12V tap routing. The black wire goes up through the tail light area and follows the tail light connector back to the Tekonsha assembly. I realize the 12V fuse is a bit out of the way to access but if I short it and it blows, it's my own fault and I'll deal with it. My bike rack and trailer lights are all LEDs.

This is the velcroed 4-Way Flat plug. It can be pulled out or just left there when in use.

s

Also a note on the EcoHitch install. Only the two side cuts on the bumper and on the dirt shield are needed. Don't make a third cut across. Just bend the bumper and shield back as needed. This allows you to trim the side cuts to closely fit the receiver.

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Hi Steve, thank you! I really like how you used a velcro solution for the plug. Funny, I also considered using a velcro option. Even saw how someone mounted this on top of the receiver (which obviously doesn't work with most of the after-market receivers for our vehicles since they're "hidden" and don't stick out as far). But in the end, for me, personally, didn't care about drilling. Although, I never considered the aerodynamics . I'm sure though, someone's going to look at this option as more acceptable, so thanks for sharing!

As for going through to the 12V in the trunk, I did see a few threads about accessing it. It's a viable option and might be easier. I just felt more comfortable going to the LVB so did it that way. But definitely another option.

Also, as for the hitch install itself, I did this two years ago before I was very active on this forum, so I just took it to an install shop. Knowing what I know now, I definitely would've installed it myself. But at the time, I just needed to get it done. But yeah, no crosscut is needed if you do it right.

Without pulling the dirt skirt to show the rubber plug from underneath (it's about a 2" plug), here are pics showing the cable coming up from underneath the car into the trunk: through the rubber plug, through slit in the carpet. The black styrofoam accessories tray sits right where it comes through but doesn't interfere. And plenty of cable length to reach outside the car to whatever you're plugging into.

GT-Papa said:

Without pulling the dirt skirt to show the rubber plug from underneath (it's about a 2" plug), here are pics showing the cable coming up from underneath the car into the trunk: through the rubber plug, through slit in the carpet. The black styrofoam accessories tray sits right where it comes through but doesn't interfere. And plenty of cable length to reach outside the car to whatever you're plugging into.

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Interesting, so you just close the hatch over the cable and there's no issue?

Correct.

GREAT writeup - thank you. I probably won't attempt this, which is usually what a say 3-4 weeks before I find myself under my car attempting it.

I always find "Black Widow" to be a hilariously bad name for car ramps. I'll stick with my Rhino Ramps, lol.

Jeff-NoVA said:

GREAT writeup - thank you. I probably won't attempt this, which is usually what a say 3-4 weeks before I find myself under my car attempting it.

I always find "Black Widow" to be a hilariously bad name for car ramps. I'll stick with my Rhino Ramps, lol.

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Thank you. That's so funny too. My friend that was helping me saw the name on those ramps and said, "I hope that's not a bad omen." ?