Blogs Car Info Our Show Deals Mechanics Files Vehicle Donation

(Mazda 3) Rear ended from behind - car won’t start

I was rear ended from behind recently. The impact left a hole in my bumper as well as took out a chunk of the absorber material from beneath my bumper. Of course there was other physical damage as well.
Currently dealing with insurance right now which has noted that my Exhaust System - Muffler & Pipe , Rear bumper, Rear lamps & Rear Body/Floor all need to be replaced.

My car which has had NO issues prior to the accident stopped working shortly after the fact. My battery has been checked and that is fine. There was a burnt scent under my hood, of which a wire near the battery was noticed that was charred. The wire was hotter than it should have been as well. The voltage coming off the battery was also higher than it should have been.

Dealing with insurance and trying to prove that it is related to the accident is currently where i’m at with things. My car is set to be sent off to a mechanic to figure out the problem. As long as the problem is related to the accident im covered, and if its not then i’ll have to pay.

Has anyone dealt with this or know what the issue may be ?

No one can guess what might be damaged after a rear end accident when we cannot see the damage. The best you can do is stand your ground. I think it is very likely the problems you have are due to the accident but that is not absolute.

The battery may have been jarred out of position causing a short. The fuel inertia switch may also be tripped.


The impact would’ve been on the side closest to the fuel tank . I’ve seen articles online about the switch being tripped.

A loose connection causes heat and the damage you see there. Probably nothing to do with the collision.

How long ago was the collision, time and miles?

The collision was a week ago . The problem presented itself within a couple of days of the accident.

There may be a fuel shutoff switch that was tripped, read the owners manual to see if so equipped and reset it.

@Barkydog can that cause the voltage being put off from the battery to be higher than it should be?

I doubt it.

When you say it won’t start, do you mean it cranks ok — that rrr rrr rrr sound – but won’t catch and run? Or do you mean it won’t even crank?

If the first, that could be a result of the exhaust system damage. The exhaust system must flow freely for the engine to run.

If the fuel pump had shut off as a result of the collision or if the tail pipe were pinched off the car would not have left the scene of the accident on its own.
Hopefully your mechanic will have an economical solution to battery cable damage shown in your picture.

@George_San_Jose1 when I tried to start the car initially, the car acted as if it didn’t want to cut on. Almost as if the battery was dead. The battery is fine though. About 12 hours later the car wasn’t starting period, just a clicking like sound when trying to start it. The radio from what I call appeared to work.

Whose insurance are you dealing with? If it’s the at-fault driver’s, stop. Call your insurance company and file a claim. They will fight the other guy’s company for you. This, of course, assumes you are properly insured.

As for not running, “it was running fine before their client hit me, and now it is not running. The causal link is clear” should be all you have to say.


@shadowfax the other persons insurance is accepting full liability of the accident since that person was at fault. However the insurance was giving me pushback about the car not starting not being related to the accident. Basically it is being said if it not related then I’m responsible for the repairs. I know my car in and out, as I’m the original owner of it. My car has been fine up until the accident. My insurance said they would handle it but go after the guys insurance, but it’s hard to know what’s going on, since I’ve had some trouble getting in touch with my actual adjuster.

If “initially” means at the accident scene, then I think you have a good argument. Make sure that you make that clear as you deal with the insurance company.

Insurance companies always claim that a mechanical problem cannot be caused by an accident. They are dead wrong.

As a mechanic I’ve seen examples of this. One was a manual transmission in a Subaru with only 15k miles. The trans was shifted a few times and locked up solid due to the shift rails being slightly bent.

Years ago I wiped out my Corvette. The engine was untouched but after the wreck the engine ((sold to someone for a project) burned a quart of oil per 5 miles. The crankshaft end play had been exacerbated by the wreck and this in turn caused several pistons and rings to crack from the impact of broadsiding someone.


If you have an insurance agent that is hard to find, contact your insurance company directly. Tell them about the issue and ask if they have a record of the claim. If they don’t, stay on the phone and make sure they record your information. Your pay them to handle all your insurance issues no matter who is at fault.

You comment above is a little unclear. When I start my car, here’s what happens: I turn the key from “on” to “start” and then hear an “rrr rrr rrr” sound for a couple of seconds, then I hear a subtle “pop” sound, then the engine starts running on its own, so I return the key to the “on” position and drive away. What did your car do or not do that was different from my description ? On the initial attempt to start it.

Update: The insurance (other parties insurance who is at fault) made me get a diagnostic test on my car at a shop. The shop said my starter was the issue. Obviously insurance came back saying they weren’t going to cover it. However I have since went out and bought a new starter, along with installed the starter. My car still isn’t working, the starter isn’t the issue. Now I’m out of money because the starter can’t be returned. My car is also smoking. I am beyond frustrated. My car was absolutely fine prior to the accident.

The picture of the burned cable that you posted is no long in your post.
Try removing that cable and cleaning the cable and main relay contact points. Be aware that the stud may be brittle and break because of the heat damage.