Car still running with battery disconnected

[JRoss6]

I hope you don't think I am crazy because Im not too sure right now.
I was first on the scene of an accident were a semi had run a small car off the highway. The passenger was wearing her seatbelt and the airbags had deployed so she was fine. The front end of the car was destroyed the
lights were all on and the engine is smoking badly and roaring. I enter the vehicle and kill the ignition.
Now here is when its gets strange. I go to the front to disconnnect the battery and had to blink several times to make sure I was not hallucinating.
The cable to the positive terminal was sitting up in the middle of the motor
completely thrown clear of the battery by the impact. Now I have only been a firefighter for a year but as far as I know and several other more experienced guys have agreed that this is impossible! The car was maybe a 1999 or 2000 Accord if that helps. I walked back to the car several times
and looked again because I just could not get my mind around it. Any thoughts?

[AC1503]

It was running like most vehicles do, from the electricity supplied by the alternator. The battery is mostly for starting anyway. I had a battery short out and explode on my pickup truck many years ago. It was blown apart, but the engine kept running.

[JRoss6]

Thanks. I thought it might be my stupidity.

[backsteprescue123]

Ron Moore had an article on this in FH mag. some time ago. He wrote about how even when the cable is disconnected, the battery can still be supplying power. Due to object implaed through battery, etc.

Maybe Ron can clarify this, or point you to where you can find that article.

[cardoc]

As AC1503 stated this is normal. The battery is only a capasitor for vehicle operations. Untill the current exceeds alternator output it will run on most vehicles. Here is a trick for you. Unplug the dist connector, coil connection on distributor ignition vehicles. Or find a power distribution center and pull fuses marked ecm, fuel pump, ignition. DO NOT pull ignition spark plug wires off as this WILL tingel alot. Alan

[LeeJunkins]

I agree with them this car being the model you posted was running off of the altenator. But today things are changing fast, so keep in mind that some of the latest models are now using Two batteries, one starts the vehicle while the other runs some of the systems. One may be located under the hood and the other under the back seat, or in the trunk. Tood Hoffman has a pic somewhere on this forum that shows a buick with two batteries side by side under the back seat.

[S8ER95Z]

Normal.

Visit a drag strip and look at all the cars with missing batteries.

[JRoss6]

Thanks again for the help. I think the confusion started because of some problems I had with my own car. I have 2002 Escalade and it has been shutting off with no warning. I noticed the positive terminal was loose, Cadillac told me this morning that in older cars they can still function off the alternator but lots of newer cars, the Escalade being one, completely shut down if the battery connection is lost. I guess it has something to do with how computerized cars are today.

[pfd4life]

Unplug the dist connector, coil connection on distributor ignition vehicles. Or find a power distribution center and pull fuses marked ecm, fuel pump, ignition. DO NOT pull ignition spark plug wires off as this WILL tingel alot. Alan

Provided you can actually ACCESS the fuse/relay panel and if they are marked yes. But I have been on more than one incident where this just is not possible. I've never gotten shocked, zapped, fried or anything else by touching a spark plug cable...I just cut them with an insulated linemans pliers form Klein Tools.

[harley4227]

I don't want to beat a dead horse, but all vehicles are designed to run off of current provided by the alternator. Once the vehicle starts you can throw the battery away. Since most vehicles today do not have a distributor, pulling that wire is out. Pulling plug wires is a bad move because there will be sparking and you are creating a potential fire hazard, plus the fact that most vehicles will still run with only 1 or 2 wires disconnected. The power distribution center (fuse box) is a good move if it is under the hood, but alot of them are being moved inside the vehicle for protection. All vehicles need two components to run........fuel and air. The fastest and best choice to shut down a late model vehicle if the ignition key can not be reached is to pull off the air intake and plug it with something like a rag. Most of the time this air intake is accessible and easy to get to. And remember......just because the engine is not turning does not mean that the vehicle is safe. The Hybrids will start any time the accelerator pedal is depressed.

[fftrainer]

The front end of the car was destroyed the lights were all on and the engine is smoking badly and roaring. I enter the vehicle and kill the ignition.

The fastest and best choice to shut down a late model vehicle if the ignition key can not be reached is to pull off the air intake and plug it with something like a rag. Most of the time this air intake is accessible and easy to get to.

Ok so am I missing something? I understand vehicle dynamics(or so I thought) to know that the alternator provides electrical power to a vehicle while running however this guy clearly stated that he entered the vehicle and killed the ignition. What's the deal? Is it that the key was turned to accessory?

disregard.... I re-read the first post and I guess he was more shock that the car had been able to run with the battery disconnected, not that it kept running after he shut it down. Been a long day... sorry!

[EFD840]

Ok so am I missing something? I understand vehicle dynamics(or so I thought) to know that the alternator provides electrical power to a vehicle while running however this guy clearly stated that he entered the vehicle and killed the ignition. What's the deal? Is it that the key was turned to accessory?

We were dispatched to an MVA where the vehicle crashed while being chased by the police.

Got on scene, the vehicle (a late model Taurus) had heavy damage to the front end but was idling smoothly. The officer walked up and said "Sorry to drag you guys out but I really didn't know what to do." He then proceeded to hand me the wrecked car's keys, which he had removed after turning the ignition off. I went and verified the ignition was in the off position but the car still ran.

It shut down while we were standing around wondering what to do. I just wrote it off to the old truth that sometimes just plain weird stuff happens.

[Chiefbeal]

"All vehicles need two components to run........fuel and air. The fastest and best choice to shut down a late model vehicle if the ignition key can not be reached is to pull off the air intake and plug it with something like a rag. Most of the time this air intake is accessible and easy to get to."

How about an air filter full of CO2? Engines don't run very well on it. Got a whole bottle of it on your NFPA 1901 pumper.
Ike

[nmfire]

He shut the ignition off. Then he noticed the battery was already disconnected and was wondering how the engine was running before if the battery was disconnected. Answer... Alternator supplies power, battery isn't needed.

Regarding shutting the key off but the engine stays running, that is simply a busted ignition cylinder. I've seen cars that you can just pull the keys out of at any time. If the ignition cylinder is broken, you can turn it anyway you want, it still won't do anything.

I wouldn't waste my time looking for fuses to pull. Starving it of air will kill it everytime.

[fireguy919]

I work at a Ford dealer. This has only happened once how ever it did happen. Came in one morning we a brand new at the time 2001 Focus that was running on the lot. The keys where in the look box and no where near the ignition switch. As some may know the Focus is among the many models that uses the PATS transponder keys. So it may one be one in a million that can run by its self, but we all know strange things happen.

[MetalMedic]

I was always taught to use the CO-2 extinguisher to shut down a diesel engine that is in run-a-way... so I think that would have been my first option on a gasoline engine as well.

[backsteprescue123]

I was always taught to use the CO-2 extinguisher to shut down a diesel engine that is in run-a-way... so I think that would have been my first option on a gasoline engine as well.

I have heard of using this technique on transit bus fires, just discharge it in the vents on the right rear of the bus I believe.

[Resq14]

It should work on any internal COMBUSTION engine... take away part of the tetrahedron just like any other type of combustion...

[MetalMedic]

I have heard of using this technique on transit bus fires, just discharge it in the vents on the right rear of the bus I believe.

That would likely be a diesel engine. On most motor coach buses, you also have a nifty "kill" switch located in a compartment on the rear of the bus. We had a local motor coach service (LAKEFRONT) bring one of their rigs to a county fire meeting once for a tour and training session. It was worth taking the time to learn a little about the construction and safety features in these things. They are not like a school bus and present some unique problems.