Why is my in-line fuse blowing !?

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After driving fine for like 4-5days … all the sudden spuddered out … and the literally nothing electrically - so I checked and my in line battery fuse is blown … put new - blew..put a 20 - blew … put a 25 - blew…
What the f*** happened ? —— a wire f***ing move? What wire should I key in on …. I just rewired everything not too long ago but it was running perfect literally perfect
 
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Need more clarification on what fuse you're talking about. Is it one of the ones in the fuse panel under the dash?
What year, what engine, all stock?
Pics?
 
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It **sounds** like the inline fuse under the hood from the battery to the main harness...if that's it, that'll be a bit harder to narrow down. My '76 had a short jumper there, no fuse...but the wiring diagram does have one in that path. I replaced the jumper with a fuse holder and re-added a 40A fuse...anything to help avoid a fire the better. 🙃

But agree - need to narrow the haystack a bit.
 
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Looking back through his posts and it might be a little more complicated lol

 
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Tis true. My rig doesn't have much load the factory circuit anymore....all lights are LED, and the ignition/fuel is on a full separate harness. Heater fan is my biggest draw at this point.

Could be the OP's issue though - although still not sure which blew there.
 
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I couldn't figure it out - had it towed home ughhhh ... today = nightmare material... since just rewired everything im thinking it must just be a couple exposed wires touching or something - but I did everything perfectly I didn't skip anything when I did this - I just never re-wrapped everything because I knew as I installed emission equipment the guys would need access to wires....Anyways, I put a 15amp fuse and it was fine for however long and drove perfectly (like 4 days) then all the sudden today it wants to burst, even with a 25amper in there...

apologies I didn't jump back on to answer everyone it was a stressful situation...esp when it was literally on the dyno when it just suddenly sputtered out because the fuse blew - like wtf...so random and so sudden. he was revving it and it was doing fine then it blew and car off, Nothing ...replaced fuse - blows again (lights work everything works) but when go to ignition and it blows right away (ONLY upon ignition it blows) - replace fuse with bigger blew again - went all way up to a 25amper and when it blew I stopped
 
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guys, that's probably my f***ing problem ! I just put an inline fuse ... and popped a 15amper in there....I dont have fusible link ...ugh thx .. but still I doubt that's the only issue going on here...or else maybe im wrong and it is....
 
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I have re-wired all that and cleaned it up with extreme attentiveness because I only wanted to do it once. So that's all better now. lol but that was a nightmare for sure. Im gunna update that post with all my pics of the really nice cleaned up look. lots of nice dual sided heat shrink. looks super neat and used all OEM wire colors - didn't stray once from that.

SO, I got it home BUT THE ISSUE STILL STANDS... After loosening my wires (because they are zip tied currently not wrapped) and being able to see them and make sure there's nothing touching, I'm gunna try to just throw a 30 ampler fuse in there and try again as I only went up to 25amper yesterday and it still popped. because honestly the f***ing thing was working fine and was driving and it all the sudden just happened in the middle of a smog test - he was revving it, it was doing fine, then all the sudden sputtered out because fuse blew...then tried to put new 15a fuse in my in-line and popped again, so on and so forth up to 25a ... decided to tow home.
 
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frustrating though because was driving fine for like 4 straight days of test driving...
no problems with my in-line fuse vs fusible line gaff - meaning the 15a fuse in my in-line was working .. car starting right up and working wayyy better than it ever has since my rewire. so im happy there but obviously still couple hiccups.

why would it be fine for that amount of time and then I drive it to the smog place - gets it on the dyn0...revvs ...sounds clean AF working just like it should. and then boom fuse blew and car spudders out...im obviously going to trace for wires touching etc but anyone have any thoughts based on that description of how this came about happening...?
 

workingdog

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I'd humbly suggesting not putting the OEM fusible link in there, but a decent resettable breaker - like a bussman. One advantage is it's easily resettable, other other is it can be manually tripped and used to disable the vehicle. I use 50 amps. The fuse is just for protection, it has to be pretty big because all the power of the rig is going through it. Don't over think why it blew when it did. Only the LandCruiser gods know.
 
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I'd humbly suggesting not putting the OEM fusible link in there, but a decent resettable breaker - like a bussman. One advantage is it's easily resettable, other other is it can be manually tripped and used to disable the vehicle. I use 50 amps. The fuse is just for protection, it has to be pretty big because all the power of the rig is going through it. Don't over think why it blew when it did. Only the LandCruiser gods know.
right - ok ill check that out because I was already researching a HEI distributer kill switch, maybe that can do both for me
 

Dynosoar

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Start with the big white and white blue wires at the Ammeter,
then check the alternator.
Dyno
 
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Given your description I would look at alt., reg. / after that I would look at the back of the fuse block, just a hunch, had a friends doing the cut out bit and two other times a mystery cut out turned out to be the fuse block, not where the fuses clip in but the bussing on the back.
 

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