Inertia Switch??

BlackenedSVT

Active Member
Jan 18, 2004
1,841
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38
New Jersey
So this kid that i go to school with was telling me about this "inertia switch" that is in the back driverside quarterpanel. Apparently when the panel is hit way to hard (for some reason) or is in an accident...the car will refuse to start and this switch needs to be reset and the car will run.

I've never heard anything abou this switch...anyone know what the hell it does and what its for??
 
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UDTBadkarma said:
So this kid that i go to school with was telling me about this "inertia switch" that is in the back driverside quarterpanel. Apparently when the panel is hit way to hard (for some reason) or is in an accident...the car will refuse to start and this switch needs to be reset and the car will run.

I've never heard anything abou this switch...anyone know what the hell it does and what its for??


it is true, Ford has used them since 1981. when the vehicel is an a collision, a check-ball trips a circuit in the switch killing power to the electric fuel pump. wthout it, a fuel pump could keep running and start a fire. even some race cars use them.
 
I have actually used that before as a fuel kill for theft prevention, depending on where i park.
You can just use your key and turn it on and off. On my year, you don't need to pull a panel off, it already has a hole to access it.
 
Well, it looks like a cylinder with the top open and the red botton exposed. (wait. did that sound dirty?)

Anyway. There is a little opening just below the top edge that just allows for a key to be inserted. You put the key in and angle it up. You will see and hear the botton pop up. That's it. No more fuel. Try to turn on the car. It will use the rest of the fuel that is already in the line and immediatly shut off.

To reverse, simply use your finger to push it back down.
 
Comes in handy when time to change your fuel filter. Keeps you from getting gas all in your face.


I used to mess with my friend's by tripping that thing when they weren't looking.

I wonder if other vehicles have them? I have never seen them in another car but then again i was not looking.
 
UDTBadkarma said:
interesting. How do you use your key to activate or deactivate the switch? This does soudn like a nice anti-theft idea.

So its connected to the guel pump?

It won't keep anyone from stealing it, but they won't get very far. I blew the fuse on my fuel pump (which essentially does the same thing), and still made it about a mile down the road before it completely died.
 
Mustang5L5 said:
Comes in handy when time to change your fuel filter. Keeps you from getting gas all in your face.


I used to mess with my friend's by tripping that thing when they weren't looking.

I wonder if other vehicles have them? I have never seen them in another car but then again i was not looking.
ALL LATE MODEL FORDS HAVE THE SWITCH
 
I know a guy that bought a car for $250 that had been rearended and would not start afterword. Does anyone want to make one guess on what was wrong? In all honesty $250 was a deal, but even running it was probably not worth more than $700
 
jstreet0204 said:
It won't keep anyone from stealing it, but they won't get very far. I blew the fuse on my fuel pump (which essentially does the same thing), and still made it about a mile down the road before it completely died.

yeah that is true cause someone tried to steal my car today :nonono: but i just saw them through the window, this was in broad daylight too :mad:, and they took off in a mini van so from now instead of just parking it on my drive way i'll be putting my car in the garage...... if they wouldv'e actually succeded in getting in the lo-jack :hail2: would've been triggered as soon as teh door would've opened

afterwards i showed my lil brtoher what happens when you trip that switch and the car was idling funny till it died :D
 
03ghoststang said:
yeah that is true cause someone tried to steal my car today :nonono: but i just saw them through the window, this was in broad daylight too :mad:, and they took off in a mini van so from now instead of just parking it on my drive way i'll be putting my car in the garage...... if they wouldv'e actually succeded in getting in the lo-jack :hail2: would've been triggered as soon as teh door would've opened

afterwards i showed my lil brtoher what happens when you trip that switch and the car was idling funny till it died :D

That's why I hate living in Fresno.... #2 in the NATION for most stolen vehicles!!!:nonono: