92 swift main fuse keeps blowing thought it was after market stereo so pulled it and still the main fuse keeps shorting???? where should i focus now?

ECU1 fuse, the correct amps rating ,correcto?10A
not reading the service manual schematics is the loss.
the electrics on cars are complex 1 fuse may run 20 things no nobody can guess what, lacking the book.
the fuse blows for and short on the feed to stop FIRE.
ECU1 runs , let me count them all, upto 12 things''
5 pins on ECU sure.
upto 3 Radiator and A/C condenser fans shorted.
purge control valve shorted. EVAP device.
2x Oxygen 02 sensors shorted, or as all LOVE to do SHORT the heater pins OUT. pin 4. or wires melted at them and touching exhaust pipe there, (loves)

last is DIAGNOSTIC MODULE FOR TANK LEAKAGE
PULL CONN # EM02. TO PROVE IT.
A TECH LOOKS AT both 02 FIRST THEY LOVE TO SHORT. AND DISCONNECTS THEM,
THEN DISCONNECT ALL listed devices 1BY1 TO FIND THE OFFENDING SHORT.
NEVER REPLACE THE MOST EXPENSIVE PArt first.
see?
see chapter power Distribution or MFI pages
pays yah 20 bucks and look?
https://eautorepair.net/Marketing/Default.asp

NO VIN or engine told. 2.2. or 4.3L
so starter spins the engine fast.
find the Fuse blowing overload cause
the wired loads to it is here.

https://eautorepair.net/Marketing/Default.asp

so your shop fears electrics,find a real shop?
ok 4.3l guess
ECM1 fuse, 15amp blows, must be 15 amp okay
ICM shorted pin A shorted ,common .
Igntion coil primary shorted
crank shaft sensor shorted
any injector shorted
fuel composition sensor shorted 2.2L ONLY
PCM SHORTED AT P19- C1

SO WE PULL THEM ALL 1BY1 UNTIL FUSE DOESNT BLOW
OR WE DO THAT BACKARDS, SAVING FUSE
PULL THEM ALL FIRST THE AND THEM 1BY1
AND WHEN BLOWS YOU KNOW WHICH ONE IS SHORTED.
read the manual is best.
guessing is for squids.

its surging need to find out what it is. after market radio, subs, amp, etc..

It sounds like just the one problem. Your tails and the dash illumination lights are all on the one circuit that the fuse keeps blowing. Don't get confused thinking of another main fuse, just focus on this one circuit..
It is very seldom that a short develops at the fuse box, it certainly can happen from corrosion or loose terminals, but it is rare. More likely is a bad wire just like the one you found near the exhaust. Somewhere very likely a wire has had insulation stripped or scraped off, soon as the wire touches metal it will blow the fuse. Were any other wires damaged in that harness for the speed sensor? Or do you see any wires hanging down from under the truck, anywhere going back to the tail lights?
If you did the stereo yourself, were any wires cut going to the dash? I doubt this as the wire for the dash lights would be in a wiring harness that is like a bundle from under the dash up to the instrument cluster. You just have to keep looking for the short.

Do you have an after-market stereo installed, if so then you could have a wire touching ground. If not then you have a component shorting out.

There is a short somewhere, do you have an after market stereo? Look for a short, or grounding out

my guess is that you have a short check the back of your stereo especially if you have an after market deck make sure no wires are touching

This could be a component or a wiring fault. It is easier to check the components so:-

1)Remove lamp and insert new fuse.

If fuse goes again, disconnect stereo, replace lamp and fuse.

If fuse does not blow the dump stereo.

If fuse goes again, trace the wiring and

If it still blows, then the stereo is likely to be faulty

Replace the wire. It is shorting to ground, causing the fuse to blow.

its shorted to ground some where