ok guys, its a 1992 Pickup 3.0 manual

so this morning the truck wouldn't turn over, but the battery would click, making us think it was just a dead battery. there was no success with trying to jump start the truck either.
a new batterey was bought and put in. all of the excessories work, but when you try and start the truck, now it doesn't even click?!?!?!?!

on a side note, (not sure if this has anything to do with it) but this morning both the EFI fuse (the small 15 one) and the interior dome light fuses were burnt out. both were replaced. does anybody know exactly what the small EFI fuse does and what would cause it to burn out? would the engine still run with it burnt out? thanks guys!

 

I'm no expert here, but EFI stands for ELECTRONIC Fuel Injection... IE it's run by electricity. You need that fuse for it to run. I have no idea why they would have burned out. Replace them and try cranking it.... if nothing I'd guess either bad connection or starter solenoid. Always a good idea to look over your power and grounds, make sure they are tight and clean. That's all I've got, good luck!

 

yeah, we know it stands for electronic fuel injectiong, but does the smaller 15 control the same stuff as the huge black efi fuse? we had already replaced it before we put the new battery in and got no click.

 

hmmm..... that is kind of odd then... No that small 15 most likely doesn't do the same duties.... what kind of condition was the old battery in? It almost sounds like you had a short or something somewhere.... cause it's odd for you battery to go dead and to blow 2 fuses overnight. Do some careful examination of your engine bay if you get a chance and have a heated place to do it..... something is fishy....

 

The small EFI fuse (15a) in the fuse block in the engine actually powers the whole EFI circuit -- the ECU, the fuel pump, etc. Mine blew for an as-yet unknown reason and I'm champing at the bit to figure out why, hopefully if the temp gets above freezing I'll haul my ass out to the drive and figure it out.

Why both went at the same time is a mystery. Water somewhere shorting things out? EFI fuse blows for damaged/corroded power lines to the fuel pump, damaged lines to the O2 sensor, blown EFI relay (silver can in the same fuse box as the fuse.) Maybe some other things too.

 

i don't know if you guys understood, but only the 15 amp efi fuse blew, not the big relay one. so does anybody know what would cause it to no longer click when trying to turn it over? and why would it stop clicking after replacing the battery?

 

bump!

 

Have you checked the starter itself? If it has an internal short on the solenoid that could be causing the fuse to blow when you try and crank it. I take it that this is an automatic or you would of tried catching it in gear with a fresh fuse in it.

 

on pirate 4x4 someone was talking about theirs blowing. the O2 sensor wires melted on the exaust, check it out....

 

found the problem! all it was, is a melted ALT80 fuse in the fuse box.

 

Glad you found the problem. Nothing like taking two days to fix a $5 part. That's what I hate about diagnoses problems.