Yes I am aware of it's purpose but as a 35+ year bodyman I have reset 3 or 4 in total ( none of which had fuel line ruptures )) and have seen some extremely damaged vehicles . I guess my point of view is that even in a horrific crash it may or may not trip and I would disagree that it does not reduce reliability as any connection , relay , switch etc. adds another point that can fail and therefor needs to be checked no mater how unlikely it being the cause of the problem . IMHO

 

The addition of any component will increase the risk of failure. so does going out side your home increase your risk of having an accident or being killed. So does that mean you never leave the house ?
It is all about risk, the chance of the Inertia switch failing is so infinitesimally small you have a better chance of being hit by lightning.

We have decades and decades of advancements of collision mitigation so no surprise there were no fuel leaks and really it is not the stuff that makes it to the collision center it is the instances where it does not where the driver or occupants were rendered unconscious or trapped those vehicles do not make it to the body shop and are written off, it is in those instances we do not want the fuel pump to continue to run potentially burning occupants alive.

Let put it this way if the impact is hard enough to rupture the fuel system the inertia switch will trip. .


We are doing install on vehicles whose base engineering dates back over 70 years and had NO collision protection no controlled crumple zones, passenger restraint, no protected fuel systems, and installs in most instances are not engineered. Not being specific here but some of the work Iv'e seen done on the board and put on the road, I sure as the F hope they installed an inertia switch.

An Inertia switch is cheap insurance to mitigate death or injury by fire, and you have better chance of being hit by lightning than an inertia switch does of failing.
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The only one I have ever had trip out on the road was in a 88 Bronco II, that was jumping a railroad track. Funny thing was my wife had a head on around a blind corner enough to cause over 5K in damage and it didn't trip then.

 

^^ Agreed. Simple to include and may as well be free from a junkyard. While they may or may not function as intended (I've heard people bitch about air bags not deploying but then they probably would if they had - no making some people happy) I've not heard of or seen one fail - ever!

 

I had a guy I worked with that had a deer run into the side of his car and tripped that switch. He had no idea why the car wouldn't run until road side assistance reset it for him..

 

The Ford inertia switch is fitted between the fuel pump relay and the fuel pump so they carry the full amp draw of the fuel pump. See below wiring for an EFI Ford truck.

 

I agree with you but the odds of the switch helping you is minimal and the odds of another connection leaving you on the side of the road is far more likely . If this makes anyone feel more comfortable by all means put it in your build

 

In the 80s, I worked in a Ford dealership as the shop forman. We were down the street from a large supermarket. During a couple of years we saw about 20 Fords and 2 Lincolns that were towed in for no start. In every ocasion, the custmer said the car ran fine before going in to the store but wouldn't start when they came out. Back then Ford mounted the inerta switch in the trunk near the rear bumper.

In all of those instances, I found the inertia switch partially tripped. Enough that the fuel pump wouldn't operate, but not enough to allow the switch to be reset. In every case, I had to smack the switch with my fist so the trigger would pop completely open. Then I could reset the switch and restart the car. I never replaced the switch on any of the vehicles.

We sumized that the cars had been hit while in the parking lot of the store by an other shopper's car or a shoping cart.

It really happened - just saying ????

 

i seen were people played tricks ,you would slam your hand in the rear fender. i never done it but was told it was easy to do. i like the ideal of adding that switch in my truck. at the speeds and frequency i will use the truck,odds of an accident are low. but it doesn,t seem fun to burn in a truck. if i have a fuel problem i will check that switch first. i think i,m going to start looking for one! thanks for the ideal !

 

Thanks, you guys always come through and give me plenty think about before doing a mod. I think I'll put one in.