Frunk Bumper Release 9V battery does not work, 12V works

louibluey

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Nice day, tore apart the frunk again. Pulled Fuse F72 to simulate dead/low 12V LVB.

At the bumper emergency release red/black wires -
Jump pack with override does work, small 12V lead acid battery does work. 9V battery (double checked with power supply does not work).

When the process starts, the resistance across the red/black wires is 47k ohm (means very low initial current). That means electronics is being powered to run the frunk emergency release process. After a moment, there is a first pulse of about a second at about 1.2A (Fluke meter DC clamp on min-max) to the little motorized gear box actuator. Then, after another moment, there is another 1.2A pulse, also about a second in time (did not break out gear to measure time or current exactly).

There could be overvoltage protection, however I strongly recommend, short of advice from Ford, to not try two 9V batteries, because 18V might damage the electronic circuits (this is not last century all relay logic, there is some electronics involved, possibly even a small micro).
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CHeil402

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Nice day, tore apart the frunk again. Pulled Fuse F72 to simulate dead/low 12V LVB.

At the bumper emergency release red/black wires -
Jump pack with override does work, small 12V lead acid battery does work. 9V battery (double checked with power supply does not work).

When the process starts, the resistance across the red/black wires is 47k ohm (means very low initial current). That means electronics is being powered to run the frunk emergency release process. After a moment, there is a first pulse of about a second at about 1.2A (Fluke meter DC clamp on min-max) to the little motorized gear box actuator. Then, after another moment, there is another 1.2A pulse, same about a second in time (did not break out gear to measure time exactly).

There could be overvoltage protection, however I strongly recommend, short of advice from Ford, to not try two 9V batteries, because 18V might damage the electronic circuits (this is not last century all relay logic, there is some electronics involved, possibly even a small micro).
Thanks for being the first (that I know of) to check this and for taking a current measurement. See this post here for details on that circuit (and my understanding). Based on the 1.2 A current draw, an 8 AA battery pack of 12 V would seem to work if you want to try that.

https://www.macheforum.com/site/thr...k-release-to-store-in-bumper.4443/post-132773
https://www.macheforum.com/site/thr...k-release-to-store-in-bumper.4443/post-135437
 
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louibluey

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Chris, Sorry, I totally forgot your AA solution. I think with one or two battery holders, that might be one of the safest solutions for in bumper battery storage. In a crash, the individual batteries probably would not be much of a problem. I worry a bit if a small 12V lead acid battery has too much energy, crushed, it might be fire or ignition hazard.

Others have used the 12V release wires, from the initial dead 12V battery episodes. This was just a lazy sunny day effort to try a 9V battery and the pulled F72 fuse to simulate a dead LVB.
 

CHeil402

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Chris, Sorry, I totally forgot your AA solution. I think with one or two battery holders, that might be one of the safest solutions for in bumper battery storage. In a crash, the individual batteries probably would not be much of a problem. I worry a bit if a small 12V lead acid battery has too much energy, crushed, it might be fire or ignition hazard.

Others have used the 12V release wires, from the initial dead 12V battery episodes. This was just a lazy sunny day effort to try a 9V battery and the fuse F72 simulated dead LVB.
When looking at the other posts I realized that I had responded to you directly over there too, lol. Anyway, thanks for digging through your car to test this. I would strongly believe based on your testing that one 8 AA battery holder would work.

https://www.amazon.com/Thicken-Battery-Holder-Standard-Connector/dp/B07WP1CYYW

I think lithium AA batteries will survive this operation the most times as they have stronger current characteristics... but for only needing to operate for a second or two, I think any AAs would work. And I like the AA approach because they're easy to find, they store for long periods of time well, and as you pointed out are likely less dangerous in a crash.
 
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louibluey

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Here is another possible AA battery holder, a short section of 1/2" electrical conduit to hold the eight AA batteries, no metal parts to corrode. It fits fine in the bumper, and should be okay with two plastic caps at either end, somehow secured in place (both the caps and conduit). The red and black wires and ring lugs reach both ends, no problem.
Ford Mustang Mach-E Frunk Bumper Release 9V battery does not work, 12V works 12V battery holder


This test with 8 "Anker" AA worked fine. I agree with Chis, although much more expensive, Lithium are more likely to have enough energy, even below 0F and in other harsh weather conditions. Anker Amazon is supposedly less inclined to leak (several years, no leaks yet).

I just held both leads on the ends to try it out. 12V DC is pretty safe, however in hindsight, you might want to use a glove or insulator one side.

Maybe add a taped on recovery string. I will give a length in inches after I recover mine from the bumper abyss below :) (fortunately no batteries were in it) The length that worked well for the Anker batteries is 15 3/4" (after too many screws to count removed from the front belly pan, the grey pipe has been recovered!). 1/2" electrical conduit is about 7/8" OD, 9/16 ID. Just convenient, heck if you get stranded near a Lowes or HomeDepot, just buy 8 AA batteries and get them to cut a 15 3/4" section for you (worst case scenario).
 
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Sweetwater

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Thank you for all the testing you have done. I get my Mach this
Sat. after 14 months. Deal is done and they are doing prep work
and Sealant exterior and interior. BUT my question is WHY are we
doing jumping and panel removal charge the battery ???
Should we not just call the dealer and say "Come fix this" ?
It must be corrected. What if you are 50 miles from home ?
Must we carry a 12v battery and charger with us ?
I just do not understand why we must work on our Machs.
 

CHeil402

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Here is another possible AA battery holder, a short section of 1/2" electrical conduit to hold the eight AA batteries, no metal parts to corrode. It fits fine in the bumper, and should be okay with two plastic caps at either end, somehow secured in place (both the caps and conduit). The red and black wires and ring lugs reach both ends, no problem.
Ford Mustang Mach-E Frunk Bumper Release 9V battery does not work, 12V works 12V battery holder


This test with 8 "Anker" AA worked fine. I agree with Chis, although much more expensive, Lithium are more likely to have enough energy, even below 0F and in other harsh weather conditions. Anker Amazon is supposedly less inclined to leak (several years, no leaks yet).

I just held both leads on the ends to try it out. 12V DC is pretty safe, however in hindsight, you might want to use a glove or insulator one side.

Maybe add a taped on recovery string. I will give a length in inches after I recover mine from the bumper abyss below :) (fortunately no batteries were in it)
The next, more adventurous, test would be to see how much current is needed to "start" the car. Theoretically, if the 12 V battery was dead because the DC/DC converter failed to top it off while the car was sitting in your garage all you really need to "jump" the MME is enough to "wake up" the DC/DC converter which should then take over and run the low voltage systems and charge the 12 V battery from the HVB. Sorry for all the "air quotes".

All of this of course depends on the proper operation of the DC/DC converter. This seems to have been fixed based on feedback on this forum.

Thank you for all the testing you have done. I get my Mach this
Sat. after 14 months. Deal is done and they are doing prep work
and Sealant exterior and interior. BUT my question is WHY are we
doing jumping and panel removal charge the battery ???
Should we not just call the dealer and say "Come fix this" ?
It must be corrected. What if you are 50 miles from home ?
Must we carry a 12v battery and charger with us ?
I just do not understand why we must work on our Machs.
Of course calling Ford is an option, but who knows how long it will take them to show up (if at all https://www.macheforum.com/site/thr...the-car-before-they-got-help.4739/post-140127). Having something like this in an emergency is certainly a benefit if you can't get another car to jump start you, or you just want to be self-sufficient.
 

Sweetwater

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Yes all you are doing is helping us. I had a 2010 Tesla Roadster with no problem
with charging. I could even dial it in the charge at the dash. That was 11 years ago
and Ford didn't get some info from this ??? I will hope mine will be OK but if it is
not and I call for this fix and they can not fix it they can buy it back under
Ohio Lemmon Law. I can't deal with this. (too old)
 

Kamuelaflyer

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Yes all you are doing is helping us. I had a 2010 Tesla Roadster with no problem
with charging. I could even dial it in the charge at the dash. That was 11 years ago
and Ford didn't get some info from this ??? I will hope mine will be OK but if it is
not and I call for this fix and they can not fix it they can buy it back under
Ohio Lemmon Law. I can't deal with this. (too old)
Be sure what your state's lemon law really says. Most don't allow one failure to fix as the sole requirement to be declared a lemon.
 
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louibluey

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I think most of the initial 12V problems have been fixed by Ford. This is all just emergency backup stuff, about like the parachute cord cutter I wore in a special pocket for one plane. Never flew without it, never used it.

This particular testing was mostly just electronics fun to answer a couple of questions, would a 9V battery work (no), would pulling fuse F72 simulate the flat 12V battery and enable the frunk bumper release wires (yes). Would 8 AA batteries work (yes!)
 

ChasingCoral

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I think most of the initial 12V problems have been fixed by Ford. This is all just emergency backup stuff, about like the parachute cord cutter I wore in a special pocket for one plane. Never flew without it, never used it.

This particular testing was mostly just electronics fun to answer a couple of questions, would a 9V battery work (no), would pulling fuse F72 simulate the flat 12V battery and enable the frunk bumper release wires (yes). Would 8 AA batteries work (yes!)
All of this is good to know. I can attest to the fact that Marlin's 12v system has stayed fully charged since Ford did the software update.
 

GrumblesTheDog

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Here is another possible AA battery holder, a short section of 1/2" electrical conduit to hold the eight AA batteries, no metal parts to corrode. It fits fine in the bumper, and should be okay with two plastic caps at either end, somehow secured in place (both the caps and conduit). The red and black wires and ring lugs reach both ends, no problem.
Ford Mustang Mach-E Frunk Bumper Release 9V battery does not work, 12V works 12V battery holder


This test with 8 "Anker" AA worked fine. I agree with Chis, although much more expensive, Lithium are more likely to have enough energy, even below 0F and in other harsh weather conditions. Anker Amazon is supposedly less inclined to leak (several years, no leaks yet).

I just held both leads on the ends to try it out. 12V DC is pretty safe, however in hindsight, you might want to use a glove or insulator one side.

Maybe add a taped on recovery string. I will give a length in inches after I recover mine from the bumper abyss below :) (fortunately no batteries were in it)
That's hilariously awesome. Nice work! Exactly how much space is back there? Surely you'd have to tape it down somehow, lest it roll around while you drive?
 

Sweetwater

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Be sure what your state's lemon law really says. Most don't allow one failure to fix as the sole requirement to be declared a lemon.
Yes I know one fix doesn't justify. I know the law and your dealer (mine did)
must provide you the info and paperwork at the time of signing.
 
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louibluey

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That's hilariously awesome. Nice work! Exactly how much space is back there? Surely you'd have to tape it down somehow, lest it roll around while you drive?
Definitely need some restraint system, and a cord in case it drops (clear down to the belly pan). @ChasingCoral suggested velcro some time back, that could work. Plenty of room for a pack or stick of AA batteries.
 

Maric

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I hope I never have need to do this, but how are you guys popping off that front bumper cover and not scratching the paint/gouging the plastic?
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