i dont know if my bronco is slowly and painfully dying, o if this is a curable ailment...
i posted a while ago the problem when it first happened
https://www.ford-trucks.com/forums/8...esting-me.html

now its happening more often. today after school, it wouldnt start at all. not even with my quickfix switch (hot wire from heater fuse in the fuse panel to fuel pump). finally i got it going, and a couple miles down the line it killed on me. so i look down and i had hit the switch and the wire fell off, but it still wouldnt start after i put it back together. i tried a couple different tries with the switch and with the pump wired through the computer like it should be, and nothing. so i looked on the fusepanel, and the fuse with the hotwire was melted. albeit, the panel cover sais there should be a 30 amp fuse and there was only a 15, but i scrounged around my truck and found the only chip type fuse i could find (which i hawked out of a power inverter), but couldnt get the switch back in there, so i just tried the normal setup for the heck of it and she started no problem!
so whats wrong here!?!?!? sometimes it will run fine and then 3 or 4 times a day ill have to use my switch. is the computer going out? is there a short somewhere? is it just something simple that im overlooking?
someone please help me out, here.

 

do you have a haynes manual? first you need to make sure all the fuses are the correct size. do not place a fuse larger then what is designated otherwise you may catch fire.

so with that all being normal whats going on? are you losing power to your fuel pump is that why you are jumping power over to it on the fuse panel.

what bronco, year etc are we talking about here.

 

sorry, its an 87. 4.9 efi. we do have the haynes and another manual one for it, and all the fuses are the right size except the heater fuse, which as i said is the one i was running the fuel pump off of.
as for normal- i didnt mean that it was normal for this to be doing it. it happened the one time a couple months ago, and then it was fine until about 3 weeks ago. i would jump it every couple of days, and then in the past week ive had to jump it alot, until today where it wouldnt work at all. so its been getting progressively worse.
"it" being, if i didnt make it clear (i usually dont...) the fuel system is just plain not working. you turn the key and the pump doesnt prime, and then doesnt pump when you try to start the truck. so usually when it doesnt work, i unplug the plug from the inertia switch and take the hotwire from the fuse panel to the red wire of that plug, hit the switch, start the truck, turn it off, then plug the inertia switch back in and the pump works just fine. i dont know why it happens, but its like the computer just needs a little jumpstart in the fuel managment area. we replaced the inertia switch and the relay, which was looking a little burnt and had some arcing, and the red wire terminal on the inertia switch plug is melted (why??? a short somewhere?)
im asking if anyone has any idea whats causing the failure or even some experience with a problem like this, which i presume is in the computer.

 

Ok, first off, anything that shows signs of melting or arcing needs to GO! There is absolutely no guarantee that any component that has suffered arcing or an overtemp. condition is functioning properly. Based on the information is the original post you could well have problems inside the harness between the FP relay and the inertia switch.

The symptoms would indicate a defective or damaged relay. You say its been replaced. How does the replacement look? Intermittent power loss during operation will cause the relay points to arc and gather soot. Check your connections particularly grounding locations to be certain you don't have issues with intermittent power loss.