OK so I bought my sisters totalled sentra and I have been working on it a little at a time. I ready to dig into it but worried about something.
The airbags never went off (which is good) but the battery was split in half pretty much. I need to get the car onto a trailor so I need to start the car. The car wont start because theres no battery. Im worried that if I put a new battery on that the airbags will go off.
Is it possible that at the moment of impact the battery split before the airbags could go off? I want to say no since 1) I dont believe this would be a good safety thing. 2) the battery sits farther back then the front bumper (of course) thus the airbags would go off first since the bumper was hit first then the battery. 3) since the car was tilting down before the accident, the rear bumper of the other car pealed the hood back. IMO more damage was done to the hood then bumper.
The actual steel member behind the bumper is totally fine too (which I believe tells the airbags to deploy)(i could be wrong here)
BUT
Last thing I wanna do is be wrong, hook the battery up and BAM airbags deploy.
Is there a fuse or relay or something I can unplug making sure the airbags do not deploy once I gave the car power again?
What are the chances that the alternator AND the battery both went completely dead before the airbags went off? Slim to none. Airbags are designed to deploy in a fraction of a second.
there are various sensors through out the car. in the front it will most likely look like this
The sensors are one time use only. so if the air bag went off everything needs to be replaced. The bags would have went off “long” before the broken battery would have been a problem.
I’ve never thought twice about hooking a jump pack or battery up to a smashed car nor have I ever heard about the bags going off after an accident.
Since your bags didn’t go off dont even think about the bags, just go along with the repairs.
I took a screen shot before you edited the disclaimer travisn…thanks man HOPE ALL GOES WELL!!! lol jk
OK thanks guys, thats what i figured. Would those sensors be in between the steel bumper frame and the front bumper plastic? If so i didnt see anything when taking the bumper off. Maybe its near the radiator area…ill have to look
It should not be possible for the battery to be split before the airbags can deploy. And to the best of my knowledge, they hold enough charge onboard to deploy, even without a battery. Of course the airbag computer would have to have power while it determines to deploy, and then tell what airbags should go off. Id imagine they would build these things to work at least momentarily without a power source.
Regardless, It shouldn’t be a issue connecting the battery.
If you want to be 100% safe, get a service manual and look up the disarming procedure for the air bags. I disarmed mine in my Blazer before since I had to go digging into the steering column to replace a switch and didn’t want to risk an airbag to the face. Have no clue on Nissan’s, but for my GM there were 3-4 different things I had to disconnect to completely disarm them that were buried under the dash, it wasn’t as simple as pulling a single fuse from the fuse box.
after power is killed to the car, there is a certain amount of time that the airbags could still deploy. In newer cars especially there is a powerpack that holds anywhere from 5 seconds to over 2 minutes of power for the airbags. So even if the battery and alt went first, the airbags could have still deployed if the sensors were triggered.
Ok thanks guys
I put a new battery in, wore my hockey helmet, not really and turned her on.
Air bags still good.
All electronics were working, I wentto start the car and it died. The battery is brand new from walmart and now it’s dead. My brother thought he saw a spark but wasn’t sure.
Is it possible the battery grounded and drained it all. Were talking dead. Not even enough for parking lights or dash lights…or is it possible I got a busted battery from walmart. Possibly someone elses return job
well sometimes they sit on the shelf forever so you should just charge it. and/or hook a car up to it. A battery won’t discharge that fast without blowing up.
So where’s the oil go btw?
I’m not doing this alone
My father in laws friend who does this on the side will be working on this. I’m just trying to get it to start so I can drive it up onto a trailer and get it over to his shop.
He will be dointhe majority ofthe work, pulling and welding I’ll be doing the installing parts etc
If the battery WAS indeed good, which it probably was, fully discharging it in such a brief period of time would make something very very hot, or cook a wire.
Could it be you think the battery is dead, since nothing powers on? Id make sure and measure the standing voltage. Over 12.4x is healthly, 12.2x is fine. You should be able to turn parking lights on down to at least 10V, which is REALLY dead for a lead acid.
To be honest, id assume the battery is fine and put the blame elsewhere. Even if you cranked the car over for a LONG time, it should have enough juice to do SOMETHING. It would be very very hard to discharge a new battery to the point where absolutely nothing happens.
Are you sure you have good, clean grounds? Id check any of the big wires off the battery to make sure theyre good and the crash didnt damage them.
I did have to move the battery ground to a new spot inorder to reach.
Since the impact was driver front, where the battery was, the ground ripped off (taking terminal with it). It did this because the ground was bolted to the front upper/inner steel, which crunched, pulling the wire, pulling the terminal.
I moved the ground to a near-by threaded hole so I could get the neg cable to the neg terminal. It has a bracket which takes 2 bolts but in the new spot I could only use one bolt.
I couldnt see that being the problem to short the battery out. Ill look at the wires closer after work. My brother did say he saw a spark down low…hmmmm
a battery needs a good wire to ground. since you are replacing metal and such, grind down a piece to bare metal and vice grip the ground cable to the car. and/or grind the area around the hole you are bolting to.
