87 F150 4x4 duel tanks 4.9 i6 efi... no power going to pumps with switch on. I can straight wire them and the pumps work. Fuel relay has power to and from it. Fuse panel has power both ways. All the checks that I have made are telling me the inertia switch is bad. Does anyone know something I do not?

 

Yeah - how to test the inertia switch!

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Your truck probably has the older style with the white button on the R side if the trans tunnel under the dash in the passenger footwell. But it could be under the steering column forward of where the clutch pedal goes, or maybe even in the R kick panel.

 

how do you test the switch? It is the one with the white button.

 

Same as any other switch or fuse - check continuity (resistance) from 1 terminal to the other, or check voltage with a load on the circuit. In your case, since you can't get the truck to run, you'd have to force the FP on to put a load across the inertia switch. Click this, scroll all the way to the bottom, & read the note in the diagram.

 

I will try that,thanks.