Help! I do not know where my inertia switch is. I've looked under the dash on the firewall to the left of my brake pedal, but I don't see it anywhere. Is there anyplace else it could be? Is it possible that I don't have one? If not, how do I relieve the pressure in the fuel line...I need to replace my fuel filter. I have a '92 f-150 flareside ext. cab inline-6 4.9L, EFI, 2tanks.
Thank you!!

 

on a 97 f150 4.6, the inertia switch is behind the interior passenger side floor molding . i usually use the schreader (spelling?) valve on the fuel rail. It looks like a bicycle tire valve. Put an old rag under it, relieve the pressre by sticking a nail into it, and you are in business. Quicker than messing with the inertia switch.