So I've spent all day digging through forums and I'm no better off. My truck leaked coolant so I tore down the block, replaced gaskets all the way up, bought a new head, and started her up. Ran BEAUTIFUL, idled for 10-15 min while I looked for leaks and such, made some adjustments, etc. NO PROBLEMS. I ran it down to the auto parts store to ensure no codes would come off, turned it off and back on, no issues, went next door to the kwik car for inspection, turned it off and it hasn't run since.

1st step was Fuel or spark, starting fluid into throttle body it almost starts then cuts back off, more fluid, same result, SO IT HAS SPARK.

I swap relays, still no humm on startup, I swap fuel pumps and sending unit, still no humm on startup, here I am now, voltometer to the pump leads, no voltage.

I have tested the relay, its good, even jumpered it, it's not the issue. I then when to the inertia switch, no power. No matter what I do I can not get any voltage in or out of the inertia switch, I am hooking my black wire to a screw and the red one into the pink/black, nada; then did the same for green/yellow, nada. I am thinking it has to be wiring, maybe I cracked something when jamming the valve cover on and it finally broke?? What are your thoughts??

Strange side note just before all this happened my fuel gauge stopped working, it worked on random days for a solid month of driving after that. I also feel like it works if I let it sit without power then goes to E when I turn the engine on.

 

What Year Ranger, very important?

I assume 4cyl engine from forum this is in

Fuel pump power looks like this

Battery-------fuel pump fuse-------fuel pump relay-----------------inertia switch------------------------------------fuel pump------------ground

Fuel pump fuse has power all the time
Fuel pump relay is operated by the computer, it grounds it to turn relay on, but ONLY for 2 seconds each time key is turned on, so have to test for voltage quickly or you won't see it

So with Key OFF fuel pump relay Base should have one slot with 12volts, from fuel pump fuse
With key ON, fuel pump relay Base should now have TWO slots with 12volts

Depending on the year, fuel pump power may be from a Fusible Link not an in line fuse

Tell me the Year and I will tell you the wire colors to look for


Fuel gauge will change when key is off, its just the spring on the needle, key on will show float level in the tank, depending on year 10 OHMs is empty, 158 OHMs full
Rangers have an anti-slosh module on the back of the instrument cluster, it can fail and cause intermittent operation and then just show empty, but a Float that sinks to the bottom will as well

 

 

There is a problem then

Fuel pump relay base should only have one 12v slot with key off

1996 should use standard automotive relay lay out, looks like this: https://www.delcity.net/images/output-for-a-relay.jpg

Main power from fuel pump fuse(#20 in engine fuse box) should be connected to slot #30 slot OR slot #87, Ford used either one, the one without 12v is the slot that goes to inertia switch

#30 and #87 are connected when relay is Closed/activated

#85 and #86 are the slots that activate the relay, one will have 12v with KEY ON, the other slot has a wire that runs to the computer, computer grounds that wire to activate the relay.

There are a few relays in the engine fuse box, are you sure you are testing FP Relay

1996 Owners manual here, it has engine fuse box layout at the end: https://www.ranger-forums.com/genera...1-models-3747/

 

I just went back out to make sure I wasn't confused and I was wrong, I get no power to #85 rather the key is on, off, cranking, whatever, no power at 85. I get 12 volts at 30 all the time.


I assumed this mean't my computer isn't telling my fuel pump to kick on. I checked the PCM fuse in the cab and its the wrong size (10 not 25) and blown. I throw a 10 AMP (all I had) in there to see if it gives me power and the second I crank the key it blows the big 20 Fuel Pump fuse under the hood. I feel like this means I have a short somewhere, right?? Im going to do a run to the auto parts store to get the right size fuses, let me know what yall think.

Oh it might be worth mentioning when I was trying things last week I tried to jump across the 30 to 87 to bypass the relay. It blew my 20 Volt Fuel Pump Fuse. My basic knowledge of electrical tells me that shouldn't happen...

 

Well gents I tracked the short from the inertia switch back to my new fuel pump, the top connector wasn't mounted right and was grounding out to the cover on the fuel pump. Fixed that, replaced the fuses and it started right up. Turns out I prolly didn't even need a fuel pump or a fuel filter, but 45 bucks isn't a bad deal. It's now leaking oil like no other but that's unrelated to this so I'll start up another thread. Thank you guys for your help!!

 

Glad to got it fixed, thanks for the update