Mystery Short

[Hikersteve74]

Im stumped.

im working on my 88 4x4le
couple months ago after a long off road trip in the bob marshal
got home unloaded gear and parked van. tried to start it a week later
and it would start, tuned over strong but seemed wasnt getting fuel.
did some trouble shooting and efi (15amp at panel) is blowing soon as engage starter
( push after market ignition button)
I checked most components in system efi relay, open circuit relay, fuel pump, ignition contacts/plug on
steering column and starter button. everything checked out with power and meter inspection.
traced wires from fusible link to efi relay to efi fuse to open circuit, starter relay and ignition wire from push button to starter
all seemed solid no short to ground. the connection at starter had a lil fluid built up in wire orafice but starter is working fine.

two major repairs i have done in last year that could be related.

1 had a major heater relay/ motor blower meltdown.
replaced blower motor and had to by pass relay plug on fuse panel that had melted... i did this by making harness with male spade plugs, wire, heat shrink to plug into female
slots on meltedplug head. then female insulated to relay. worked for about 3 months then wires got loose arched and ended up disengaging as it was summertime.
i bring this up because it is directly below starter relay on fuse panel. From what i can tell lookin at back of it there is no damage to starter relay plug in and i checked relay with meter
and connections and they checked out. still it is very close vacinity to melted area. Have a complete 88 le 4x4 parts van so i can swap out fuse panel.

2 about a month prior to this problem the main fusible link next to battery compartment finally failed. just the standard came off clip rubbed through and shorted to body scenario is what it seemed to be
replaced with heavy duty fuse and its been fine ever since.

Replaced fuel pump in tank about two years ago and have oversized tires that rub slightly in hard turns , and have been battling kick down cable ( throttle body to transmision) binding issue for couple years.
besides that solid, 20 mpg and goes 85mph pretty easily.

Any tips on what could be making the efi fuse 15 amp blow instantly would be appreciated. im in NW montana and winter just decided to show back up with a vengence but i plan on pulling fuse panel out of parts van next week
and trying to do some serious wire tracing/testing...
i am relatively certain that ECU is a match as van is identical even in color...year,make, model transmission and bells and whistles.

[Hikersteve74]

hmmmm not sure what i did or said but 182 views no responses??

got fuse panel out of parts van and its supposed to be in the 40s tomorrow here in nw montana so im gonna work on swapping

fuse panel and troubleshooting...
anyone else ever had the EFI fuse (15 amp) blow continuously?????

[Burntboot]

Any time a modification is made from factory, it adds an element of mystery and makes diagnosis more difficult.
I realize that doesn't help your situation but might explain the lack of responses.

Replacing FL1.25 with a fuse is not recommended procedure, Tim explained why in the fusible link thread, but I don't remember the details

If it were me (being that I hate electrical diagnosis) I would start with the easy stuff
Like pull the trigger wire off the starter, instal a new fuse and hit the start button and see if that fuse still blows
or
If the ign switch start circuit is still active, does the fuse blow when articulating the key to the start position.
or
with the ign switch in the off position, does hitting the remote start switch still cause the fuse to blow

Work thru as many scenarios as you can to try to eliminate things that aren't in play and see what it leaves you with.

As far as the other repairs go, no idea, but it is worth going back over and double checking everything.
The more variables you can eliminate, the better.
Knowing the parameters in play when the fuse blows should help guide you in the right direction
(This assumes that you've already gone thru and verified that all the usual suspects (battery connections, ground cables.....))

With recurrent binding issues on the kickdown cable, its probably worth verifying that you have a good engine to chassis ground connection.
If the ground path is being forced thru that cable, no good will come if it.

[Hikersteve74]

thanks for response and tips.
i was skeptical about the repair i did on fl1.25 and maybe should read a lil more into tims thoughts
i do have some pretty good knowledge of electronics, i like to think lo...l i worked in car audio and electronics and a couple
years as electrician, but im not an expert in the field and as i said i was skeptical, but didnt see why it would be bad as long as
i calculated the fuse size.
Anyways i will see if i can find tims article and check out some of the other things you brought up
Thanks!

[Hikersteve74]

Also thanks for your advice you brought up a couple easy things i should recheck before gettin into whole fuse panel swap.
ANd they are simpler than how i was doing them :doh: