Auto accident damage

The inertia switch tripped and needs to be reset. As near as I can tell from the drawing, it appears to be on the left side of the trunk, approximately under the left edge of the rear window. If there is carpet on the side of the sheet metal brace, it will be behind that carpet.

I am confused. You asked about the stalled engine, I explained that it is caused by a tripped inertia switch, which is its job in a crash, and that you need to reset it. That is a common problem with Ford products and can be easily diagnosed from your description. You surely do not think I can diagnose a body problem without seeing the car. That is a job for the people at any body shop, but they will send someone outside to actually look at the damage. If the bumper cover is misaligned, there is almost certainly going to be minor structural damage behind it too.

The switch you want to check (button on top) is in the trunk and the drivers side. Here is a diagram (below).

Please let us know what you find. We are interested to see what it is.

Cheers, Ken

If the car runs you do not need to reset the switch. Can you send us pictures of the damage so we can get an idea of what you need? Please upload them here.

The purpose of the system is if you get in a crash that ruptures a fuel line, the electric fuel pump would continue pumping raw gas onto the ground where it would become a serious fire hazard. On all car brands, with no fuel pressure in the line, the engine will stall. When it is not running, signal pulses are no longer generated by one or two sensors on the engine. In response, the Engine Computer turns off the fuel pump relay so the pump stops dumping gas on the ground.

Ford went a step further by adding the "inertia switch". The idea was if you get in a crash bad enough to break a fuel line, it would be hard enough to cause a metal ball to move and short out the wire feeding the fuel pump. Rather than blowing a fuse, it trips a circuit breaker built into that inertia switch. Pressing a reset button is a lot easier than searching for and replacing a blown fuse. I'm not aware of any manufacturer other than Ford that uses an inertia switch, but there could be a few.

Where the misery comes in is the inertia switch can be tripped from a lot less than a crash. Going over a speed bump too fast will do it. This was also a trick used by cops trying to stop a fleeing driver. If they could hit the side / rear of the fleeing car with their front bumper, it could trip the inertia switch, then the bad guy had no choice but to coast to a stop. Even a pot hole can be enough to trip the switch, so it's a good idea to know where it is. Yours is in the trunk, on the left side, as shown in the previous drawing. There might be carpeting covering it. Some Ford trucks had that switch inside, under the dash. If it is ever removed, it's important that it be reinstalled in the correct orientation. If it's tipped a little, it can trip too easily.

In your initial post, you said the engine stalled after the car was hit. That symptom is extremely common, and it shows the inertia switch was doing what it is supposed to do. That's why I described how to reset it. Since your engine is running now, either someone else reset it for you, or as brother Ken said, it never tripped.