Adding a Physical Interior Liftgate Power Switch

[HughJazzol]

I used a steel automotive wire fishing tool. Also known as a coat hanger.

A "Steel Automotive Wire Fishing Tool" or SAWFT. Interesting, ingenious, and comical.

I used a 14ga copper ground wire from a piece of Romex and thought I sent you a video Norman of me doing that?

You're undoubtedly correct Mark, I just looked at the 2nd video again. I was thinking of using something copper-esque to fish the wire through.

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[austinsf]

Thanks for posting this! Very interested in attempting this on my 23 GTPE. Just go confirm my understanding:

• Buy a button — like this one recommended here
• Pop open the center console (like here), to find the park assist switch. This switch is already connected to the body control module/BCM, so there is no need to run a wire like the 2nd to last photo in this post.
  • This is the part I'm most unsure about. Maybe I misunderstood and I actually need to run a wire?
• The switch linked above comes with two wires.
  • Connect one wire to the Green/Brown wire
    • Is it dual colored, or could it be one or the other?
  • Connect the other wire to the one from the BCM.
    • Again — does this already exist under the park assist button, or is this something new I need to run?

I'm completely new to making modifications to vehicles so bare with me on this (dumb) question, but how would I go about connecting the wires of the switch to the existing wires without soldering? Would something like this — "Quick Splice Wire Terminals T-Tap", work?

 

[markboris]

Thanks for posting this! Very interested in attempting this on my 23 GTPE. Just go confirm my understanding:

• Buy a button — like this one recommended here
• Pop open the center console (like here), to find the park assist switch. This switch is already connected to the body control module/BCM, so there is no need to run a wire like the 2nd to last photo in thispost.
  • This is the part I'm most unsure about. Maybe I misunderstood and I actually need to run a wire?
• The switch linked above comes with two wires.
  • Connect one wire to the Green/Brown wire
    • Is it dual colored, or could it be one or the other?
  • Connect the other wire to the one from the BCM.
    • Again — does this already exist under the park assist button, or is this something new I need to run?

I'm completely new to making modifications to vehicles so bare with me on this (dumb) question, but how would I go about connecting the wires of the switch to the existing wires without soldering? Would something like this — "Quick Splice Wire Terminals T-Tap", work?

You are confused.
You mention to buy a push button switch. Then you mention to use the Park Assist switch. You would be using one or the other, not both. Either install a push button switch to activate the liftgate or use the park assist switch.

If you will be using your own switch, then one side of the wire to your switch goes to the brown wire on the BCM that I referred to in the first post of this thread and the other wire to the switch goes to ground. That simple.

If you are going to use the park assist switch, you only need to run a wire from the brown wire of the BCM to the Green/Brown wire of the park assist switch. The wire is Green with a Brown stripe. That simple.

 

[austinsf]

You are confused.
You mention to buy a push button switch. Then you mention to use the Park Assist switch. You would be using one or the other, not both. Either install a push button switch to activate the liftgate or use the park assist switch.

If you will be using your own switch, then one side of the wire to your switch goes to the brown wire on the BCM that I referred to in the first post of this thread and the other wire to the switch goes to ground. That simple.

If you are going to use the park assist switch, you only need to run a wire from the brown wire of the BCM to the Green/Brown wire of the park assist switch. The wire is Green with a Brown stripe. That simple.

Thank you for the clarification! What guage of wire do you recommend using? Would something like this — "Quick Splice Wire Terminals T-Tap", work for tapping the brown BCM wire?

 

[HuntingPudel]

Thank you for the clarification! What guage of wire do you recommend using? Would something like this — "Quick Splice Wire Terminals T-Tap", work for tapping the brown BCM wire?

Wire gauge can be as small as 32AWG since it only carries a reference to ground signal. I used 28AWG (and I had to be fancy and buy brown wire). ??

Personally, I hate any sort of taps that pierce the wire. That said, the red ones in that kit should work. ??

 

[scott_77]

This is awesome.
1. Does doing this mod on a ’24 disable the function from the touchscreen?
2. Do you know what the other two (purple?) wires under the useless switch do and where they go? Any reason not to just use one of the two purple wires instead of running another wire?

 

[HughJazzol]

This is awesome.
1. Does doing this mod on a ’24 disable the function from the touchscreen?
2. Do you know what the other two (purple?) wires under the useless switch do and where they go? Any reason not to just use one of the two purple wires instead of running another wire?

Scott
No, it won't disable because we're taping into the brown wire by the bcm, thus adding a second switch.
The other wires under the switch are to be left alone. One is the ground, I know.

 

[scott_77]

Scott
No, it won't disable because we're taping into the brown wire by the bcm, thus adding a second switch.
The other wires under the switch are to be left alone. One is the ground, I know.

Yeah. Those were ignorant questions on my part.
After actually doing this mod, which was detailed out pretty much to the “t”, the switch harness shares hazards so obviously those are for that. And instruction was clear on tapping in. My mistake.
That being said, hardest part for me was stripping that little brownish kinda purplish wire without cutting it. Eyes aren’t so good these days.
Needless to say… another success story.
Thank you Mark B!

 

[markboris]

Yeah. Those were ignorant questions on my part.
After actually doing this mod, which was detailed out pretty much to the “t”, the switch harness shares hazards so obviously those are for that. And instruction was clear on tapping in. My mistake.
That being said, hardest part for me was stripping that little brownish kinda purplish wire without cutting it. Eyes aren’t so good these days.
Needless to say… another success story.
Thank you Mark B!

You're welcome Scott! Earlier this year I was talking to my friend that inspired me to do this mod back in early '21. I was wondering how many members here had done it after I posted this 4+ year old thread that has close to 90K views so I spent a bit of time going through it. Just the ones that posted they did it was over 50. I can imagine there are many more. Every Ford car/SUV I've owned (even my 1969 Mustang) has had a physical trunk/liftgate switch. Still don't understand why the Mach-E does not have one in its 5th year of production.

 

[HughJazzol]

Ok, so with a rainy day in town, I finally dove into this. I unplugged the pcm module, pulled the sheath back, and looked at the wires with good and white light. I entually found a very thin solid brown wire, or so I think. I hung the hook from it.
Is that the one to tap into?
There's only a blue solid one and not many other ones. The rest are striped.

 

[scott_77]

Ok, so with a rainy day in town, I finally dove into this. I unplugged the pcm module, pulled the sheath back, and looked at the wires with good and white light. I entually found a very thin solid brown wire, or so I think. I hung the hook from it.
Is that the one to tap into?
There's only a blue solid one and not many other ones. The rest are striped.

That's it. I just did this yesterday - i very very carefully skinned the jacket carefully to expose a spot of copper without damaging the strands of copper behind the jacket to test it first before going all in (couldn't find a wire tap for this small of wire locally and didn't want to wait a day for amazon ). But I kept it all plugged in as opposed to what you did (I couldn't figure out how to get the harness to free up to make it easier to access like you did - was trying to push center tab different directions while applying what felt like took too much force so stopped as I was afraid I'd break something).

 

[HughJazzol]

Ok.
I connected it all, I test, and pressing that button does nothing.

II double checked the simple wiring and no response.

EDIT - if i use the screen button to open, I can interrupt it with the park assist button. And i can close it. But, I cannot open it from a closed state with the PA button.

 

[HughJazzol]

This is what it looks like at the pcm, and the new red wire is unmovable

 

[scott_77]

This is what it looks like at the pcm, and the new red wire is unmovable

Well, i was skeptical about using one of those types of splices for these itty bitty wires... wasn't feeling confident that they'd make good contact if not lined up perfectly (assuming that one is good for the 24 AWG wire you tapped into).

I am sure you got the correct wire.

For what it is worth, here is precisely what I did... I lifted the center console up which is held in place by 4 clips to make sure I could see what I was working with. I then turned my gaze back at the fuse box/harness area, carefully skinned the jacket of the solid brown (kinda purplish) wire at the BCM to expose the copper. I then cut the green/yellow wire under the switch, stripped it back, connected a 24 awg wago connector to it, then connected a spare 24 awg wire to the wago connector as well, then, before running the wire through center console to fuse box area, just took the other end of my spare 24 awg, stripped it, and pressed it against the exposed wired, pressed button and it opened it right up for me.

It was after then that I fished the line through center console (I used a solid, bare 18 awg picture hanging wire and pushed it from passenger side seat area under the center console, then used one of those magnets on a flexible stick to pull the hanger wire up through that narrow area, then taped the spare 24 AWG wire to it and pulled it through to floor and just used a plastic spudger to tuck it up under the plastic center console to the fuse area).

At this point I carefully removed part of the jacket mid line (stripped wire in two spots about ⅛" apart at the area I already scraped the jacket from, then peeled the jacket off in that ⅛" area, then wrapped my stripped wire running from switch to there, twisted around (much like what it appears Mark did in his first post image) and taped it up.

 

[HughJazzol]

thanks @scott_77
I appreciate your help.

After an hour or so in that weird position by the passenger well on a small stool, I called it a day for now.

As I said in my last edit, pressing the button from a closed state does nothing.
If I open the trunk with the screen button, I can interrupt that with the PA button, and I can get it to close. Fully closed, pressing the PA button does nothing.

I feel that my wire tap is making some sort of contact, but perhaps not a full one. I stupidly didn't bother to test my cable for continuity to insure no cuts or nicks to it; it looks like it's in good condition, but you never truly know. The fact that I can interrupt the opening when using the screen button, tells me that I have a solid cable all the way through.

I shall continue with this some other day, and hopefully get @markboris 's thoughts. I predict that he will say that I should have used the positap, but I found what I bought cheap at Harbor Freight, and I only needed ONE. I won't be splicing many more wires.

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