Originally Posted by dagray3
am I just checking for voltage across the intertia switch to see if it's still getting juice?
You are checking from the wires on the inertia switch to ground (body of truck). Yes you are checking for "juice" (power).
Originally Posted by dagray3
also, where does the 'hot' for the high press fuel pump come from? Is it from the FP relay or the EEC relay?
FP Relay by way of the inertia switch.
You can use voltmeter rather than a test light but the voltmeter will not load the circuit and will give you a false reading that you have power when you do not sometimes. Then you will look in the wrong place for the problem sometimes for days.
You need to see what is happening at the same time to know what is going on.
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