Re-Fuel Pump 93 Explorer

[Robert3916]

I posted a thread about Fuel Pump problem about 3 weeks ago, found voltage
going back to pump Ok. Turn key on and 20 Amp fuse (#18) blows within seconds. Disconnected connector at tank and tested for shorts.(None)
Unplugged Inertia Switch and cranked over engine fuse does not blow. Bypassed power line from Inertia Switch with 12AWG Red Wire(w/20AMP in-line fuse about 5 foot from pump) and 12AWG Black Wire directly grounded to battery. In-Line fuse on jumper wires still blows when engine is cranked. Prior
to this I had tank out of vehicle and had ran same jumper wire setup to pump
with in-line 20AMP fuse(hooked up to the battery on my Astro(running) with
5 gallons of gas in vehicle. Ran pump for about half an hour at 45PSI with out
fuse blowing. (I had fuel recirculating in tank with shut-off vavle on gauge set-up to put load on pump.) My question is that is it posssible for a working
pump to draw a load at just cranking over the engine to cause the fuse to
blow with in seconds? Second question is it possible for another component
cause a load to go through my PCM to cause this failure in the fuel pump circuit?


Thanks Bob, (Robert3916)

 

[Burns]

This is something i dont think you have tried. It was hard to ready your message but thats ok

Unplug the fuel pump and replace the fuse. Plug everything up but the fuel pump. Try cranking the explorer over and see if the fuse blows.

 

[Robert3916]

Did this and fuse still blowed.

 

[Burns]

Did you try unpluging it at the intera switch and then trying to start.

 

[Robert3916]

Tried that without pump on circuit, fuse did not blow. Plugged back in and fuse blows.


Thanks

 

[e39dream]

there's a little trick listed in the chilton's manual that shows you how to jumper a connector under the hood to ground to run the fuel pump- are you familiar with this? I can scan the page if you'd like. I'm wondering if the fuel pump relay is bad?

 

[DeRocha]

When you by-passed the inertia switch you indicate the 20a fuse on the jumper wire blew.. Did you use the fuel pump wire, or did you wire it directly to the battery? To eliminate the fuel pump & wiring as the source of the problem you need to run a jumper wire directly from the battery to the fuel pump with a 20a fuse.. If the fuel pump runs fine it indicates the problem lies elsewhere..

 

[Robert3916]

Thanks, I have a couple of manuals for this vehicle.

 

[Robert3916]

No, I just ran a jumper wire from the pump to the inertia switch connection in the vehicle. I had bought some 15AMP fuses to try a run like you say directly to the battery
for both positive and negative from the pump. If it blows this fuse(like you say) it has to
be the pump drawing to many AMPS.

Thanks for the help, Bob

 

[Robert3916]

Hooked up directly from Fuel Pump to battery, 15AMP(In-line) fuse blew within seconds. I
guess is time to take the tank off again and replace complete Sender Unit.(Lucky
when I put it on a few weeks ago thinking it was OK that I used all new bolts coated
with Anti-Seize Compound.

Thanks for all who helped me out with this post, Bob