voltage at fuel pump
#1
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voltage at fuel pump
I'm having some trouble with my '96 f150. It's a 4.9l, 5 spd with dual tanks. For a while now it has will randomly sputter and sometimes stall, usually in colder weather. Normally I can let it sit for a few minutes and it fires back up.
Last Monday, it ran fine. I turned it off when I got to work, but when I came back out for lunch a few hours later, it wouldn't fire up. Engine cranks over just fine, but I didn't notice the fuel pump come on when I turned the key. Turns out neither pump will come on. I measured the voltage at the front tank and only got 7.6 volts on one of the pins with the engine cranking. From what I've read, I should be getting at least 10.5 there, right? What would cause a low voltage to be output? I measured 12 volts at the inertia switch as well. I haven't pulled the instrument panel cover off to check the selector switch.
Last Monday, it ran fine. I turned it off when I got to work, but when I came back out for lunch a few hours later, it wouldn't fire up. Engine cranks over just fine, but I didn't notice the fuel pump come on when I turned the key. Turns out neither pump will come on. I measured the voltage at the front tank and only got 7.6 volts on one of the pins with the engine cranking. From what I've read, I should be getting at least 10.5 there, right? What would cause a low voltage to be output? I measured 12 volts at the inertia switch as well. I haven't pulled the instrument panel cover off to check the selector switch.
#2
my 87 does the exact same thing! I replaced the fuel pump relay and you can hear the relay click on and off, but some reason the pumps are not priming like you said. Im thinking about the selector switch too but idk hahaha
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Not hard at all. There are 2 long thin rectangular panels that you have to pop off on the front of the plastic facing around the gages and there's a screw behind each one. Then it just pops off after you pull the headlight **** off. The switch is held on with 2 screws on the back side of the plastic facing. Before you buy a new switch, do a continuity check on the old one as well as checking the incoming voltage just to rule that out. The switch was only $15 at O'Rielly though, so you're not going to be out much either way.