Car won’t start. Locked out. Making loud banging noise

[generaltso]

if the 12v was really low, you would have had to left a running vehicle connected for 1/2hr- 1hr to get a meaningful charge into the 12v. Not just a momentary 'jump'. It has to have enough juice into the 12v battery to start the onboard computers and keep them running long enough to get the big battery turned on and get you home if the system is not charging correctly.

Sure, if the car’s 12V charging system isn’t working and you want to drive home. But any ICE vehicle hooked up correctly should be enough to start it. Sounds like that didn’t happen.

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[dtbaker61]

Has been fixed. Apparently just needing the hubby’s f150. Got me going and home. Will try the car tomorrow and if it’s still giving me issues we will take it to the dealership. Thank you all for all the help and support! I truly appreciate it.

it is quite possible that the old chevy van they were trying to charge from had a shitty alternator.... if the EV 12v was really dead, it might have been trying to pull 75-100amps, which the old chevy might not have put out, but a newer f-150 could.

I have used my 12v to export charge to a dead battery, and it started the charge at 95amps! dropped pretty quickly to 60 and then 40 for a while as the voltage in the dead battery came up.

 

[the golden eel]

Tesla has a similar system for opening the frunk in case of 12-V battery problems. I have seen reports that a small 9-Volt battery (such as commonly used in smoke alarms) will work to open the frunk, but I have not tried it on our Tesla or MME. Has anyone tested this?

I'm also curious if anyone has tried this on an MME. We sometimes use a 9V battery at work to wake our 12V controls if we don't have a power supply around.

 

[dtbaker61]

I think I should print instructions on jumping the 12 volt battery, with an arrow as to where the red and the black wires go, tape next to the battery. Also steps to connect, and then to disconnect. I do have that 12 volt jumper battery in the frunk. I've never used it on my car, but helped other people with their's.

there *should* be easy access panel to 12v connection points, and the HV disconnect. Would be a logical place for a sticker and instructions for owners and tow trucks don't ya think @Ford Motor Company ?!

 

[dtbaker61]

I'm also curious if anyone has tried this on an MME. We sometimes use a 9V battery at work to wake our 12V controls if we don't have a power supply around.

might work to pop the hood, but then no good for putting any substantial energy into the 12v to keep the MME running unless the DCDC system kicks in and starts transferring energy from HV

 

[generaltso]

I'm also curious if anyone has tried this on an MME. We sometimes use a 9V battery at work to wake our 12V controls if we don't have a power supply around.

Yes, it doesn’t work.

 

[the golden eel]

might work to pop the hood, but then no good for putting any substantial energy into the 12v to keep the MME running unless the DCDC system kicks in and starts transferring energy from HV

Yes, sorry. That's all I meant, if it would pop the hood.

 

[the golden eel]

Yes, it doesn’t work.

Bummer, thanks.

 

[dtbaker61]

Sure, if the car’s 12V charging system isn’t working and you want to drive home. But any ICE vehicle hooked up correctly should be enough to start it. Sounds like that didn’t happen.

like I said.... if the 12v was really bad, like 10.5-11v.... an old ICE with a 60amp alternator might NOT have gotten any energy in. They have a self-reclosing breaker that protects from overload and resets.

that would explain why a charge from new f150 would work

 

[rystam07]

Just kidding. Got to work this morning same issue now. Husband heading to jump me and then taking it to the dealership.

 

[rystam07]

- make sure you know your 'door pillar' code. If there is any juice left, you can at least get in and pop the hood manually. I keep mine written on a card in my wallet. I'd also suggest practicing a few times since it can be difficult to 'wake up' the door code buttons.

- using the front 12v hood opening leads will NOT work unless the 12v is dead.

There was no juice left. Code wouldn’t work in door. Doesn’t even light up.

 

[rystam07]

like I said.... if the 12v was really bad, like 10.5-11v.... an old ICE with a 60amp alternator might NOT have gotten any energy in. They have a self-reclosing breaker that protects from overload and resets.

that would explain why a charge from new f150 would work

Died again today at work. Did it maybe just not sit long enough on the charger? Go to the dealer?

 

[dtbaker61]

Died again today at work. Did it maybe just not sit long enough on the charger? Go to the dealer?

this just confirms that the internal charger/software is not working properly to move energy from HV to 12v. Essentially like a 'bad alternator'. Jumps will not work, you MUST get to the dealer for diagnostics to figure out why the 12v is not getting charged.

 

[rystam07]

this just confirms that the internal charger/software is not working properly to move energy from HV to 12v. Essentially like a 'bad alternator'. Jumps will not work, you MUST get to the dealer for diagnostics to figure out why the 12v is not getting charged.

Thank you! Heading that after I get jumped.

 

[Mach-Lee]

Died again today at work. Did it maybe just not sit long enough on the charger? Go to the dealer?

You either have a huge drain or your 12V battery is bad and needs to be replaced. Park it at the dealer and let them look at it. Leave it unlocked so they can get in with a dead battery.

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