2004 Ford Ranger fuel pump inertia switch faulty?

I deliver a rural mail route in my truck, so I'm doing a lot of getting out and have to kill the engine when I do. Four times today when I killed the engine and got back in, it wouldn't start. Sounds like its not getting fuel. On each occasion I pushed the reset button and tried to start it. It would take a few tries but it eventually started each time. My fuel pump is new so I doubt that's it, is the inertia switch the likely culprit? Ford dealer wants $140something for the switch, I don't want to waste money if that's not the issue, but seems to me like that's gotta be it. Your thoughts?

It has a relay in it to for the fuel pump

If you need a fuel switch for your Ranger you can get a decent used one on Ebay from $15 - $50. Don't pay the stealership for an over priced switch. Since you've already changed the fuel pump - did you also change the fuel filter? When changing the pump you should always install a new filter.