question about frunk situation with low 12V battery

[astrorob]

in a half asleep haze this morning, the thought occurred to me that if you could install a switch that would cut the 12V power from the frunk actuator, then you could avoid the problem where the override system does not work due to low battery voltage, as in the case the infant stuck in the car the other day, or in the situation with the update where people were routing string to the front door handles inside the car.

in theory you could route this switch down to the front bumper access panel so that you could throw the switch before energizing the emergency open circuit. i suppose if you wanted to get fancy you could use the presence of 12V on that override to open the switch, but i'm not sure if the latch assembly would be happy with a simultaneous loss of car 12V and application of backup 12V.

has anyone looked into this? is it even remotely possible?

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[Mach-Lee]

in a half asleep haze this morning, the thought occurred to me that if you could install a switch that would cut the 12V power from the frunk actuator, then you could avoid the problem where the override system does not work due to low battery voltage, as in the case the infant stuck in the car the other day, or in the situation with the update where people were routing string to the front door handles inside the car.

in theory you could route this switch down to the front bumper access panel so that you could throw the switch before energizing the emergency open circuit. i suppose if you wanted to get fancy you could use the presence of 12V on that override to open the switch, but i'm not sure if the latch assembly would be happy with a simultaneous loss of car 12V and application of backup 12V.

has anyone looked into this? is it even remotely possible?

FYI I want to correct some incorrect info you stated, the emergency frunk opening system does work as designed. The most recent incident was a dead 12V battery, and the frunk didn't open because the roadside technician did not know how to use the override function on a lithium jump pack (operator error). The previous incidents were a software glitch, so the 12V battery wasn't dead, and therefore the override didn't open (as designed) since the 12V battery was not dead.

I also want to recognize there is a lot of panic and paranoia happening right now over the 12V issues, which has gotten overblown IMO. Yes a lockout can happen, but it's RARE. There are roughly 160,000 Mach-E's in the USA, and there will be the occasional bad problem that pops up. Just because a couple vehicles out of 160,000 have a problem doesn't mean we all need to become paranoid. Dead batteries happen in all types of vehicles (ICE and EV), it's not unheard of. Let's keep things in perspective—this is a rare event, not something to fear every day.

If you get locked out, just call a locksmith to open the door or roadside to get a jump and make sure they do it correctly. And replace your 12V battery on schedule every 3 years. That's really it.

 

[astrorob]

FYI I want to correct some incorrect info you stated, the emergency frunk opening system does work as designed. The most recent incident was a dead 12V battery, and the frunk didn't open because the roadside technician did not know how to use the override function on a lithium jump pack (operator error). The previous incidents were a software glitch, so the 12V battery wasn't dead, and therefore the override didn't open (as designed) since the 12V battery was not dead.

ok sorry, i conflated the two.

i'm not really fearing it on a day-by-day basis. but IMO tesla's design is bad and apparently ford decided it's not an EV unless the doors work like a tesla. i think it would have been better to just have a physical key; that would make the whole 12V management system a little less risky.

you're probably the only person on this forum that would even remotely know if this idea is feasible... is the frunk override something handled by a computer sensing that 12V or is the backup 12V connected directly to the actuator?

 

[Mach-Lee]

you're probably the only person on this forum that would even remotely know if this idea is feasible... is the frunk override something handled by a computer sensing that 12V or is the backup 12V connected directly to the actuator?

I'll explain how it works. The frunk module handles the emergency opening by itself. It will use the external power source to run the hood release motor. It will only allow that when there is low 12V system voltage. There is a small computer chip in the frunk module that powers the motor, not directly from the leads.

So you want to add a switch that cuts power to the frunk module to force it to work or something. It's possible, but I don't think it's necessary because the chances of needing it are so limited and rare. It will already work when the 12V battery goes bad without any modifications.

 

[astrorob]

I'll explain how it works. The frunk module handles the emergency opening by itself. It will use the external power source to run the hood release motor. It will only allow that when there is low 12V system voltage. There is a small computer chip in the frunk module that powers the motor, not directly from the leads.

So you want to add a switch that cuts power to the frunk module to force it to work or something. It's possible, but I don't think it's necessary because the chances of needing it are so limited and rare. It will already work when the 12V battery goes bad without any modifications.

ok thanks. i just think it’s in the spirit of adding jump points to the plastic cover over the battery, etc. breaks the dependency loop on the 12v battery state blocking you from accessing the 12v battery.

i’m not necessarily going to do this but it just occurred to me it might be possible for someone so motivated.

 

[chillyWilly]

I once had a 2013 C-Max, my wife’s car. Drove to work one day, end of day wouldn’t unlock and nothing. No lights, no click. Pulled the physical jet out of the fob and opened door. Opened hood and couldn’t find battery. Quick online search and it’s in the rear under the panels. Could not open rear with no power. (No keyhole). So, had to “jump” to finally open hatch using the terminals available in engine compartment Being proactive I didn’t even bother jumping to start, replaced the battery outright since I didn’t want my wife getting stranded. It was an interesting few hours.

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