humboldtMUD

was wondering if anyone had any ideas on how to trace what is causing my engine fuse to blow. normally i could do this pretty easy but it blows at totally random times. prob started after i left it sit for 13 days

i really dont want to unhook stuff and wait for it to blow or not blow as sometimes it will go a few hundred miles with out blowing.

is it possible the alt is doing this- im pretty sure it only has blown once running?

i checked most of the wiring for obvious problems and cleaned up any shady looking wiring
any ideas would be appreciated - 88 22re

wyoming9

iTrader: (1)

Has anything quit working?

Could be a rubbed wire almost anyplace causing it.

It just happens at random times no pattern at all.

Chickenman

Pull up the wiring diagram and then trace the line to the fuse and find your short!

humboldtMUD

after it pops everything works perfect, this morning before i went to work it blew, put a new fuse in and drove up the hill (mostly off road and pretty far, would think if it was a wire hitting something, bumps would make it happen) but nothing happened.

i looked through most of the things that run through the eng fuse- again i cant trace a short when it isnt there, but did check connectors and grounds.

any thoughts on the alt going bad - rectifier maybe letting too much current through (like a spike)?

it happens most of the time when i first start it, but has happened when just driving on pavement not doing anything.

humboldtMUD

well i talked to my mechanic buddy and he thinks it very well could be the alternator (or alot of other things)-i will get a napa 80 amp and see what happens. will post as soon as the fuse blows or in a week when it doesnt

ChefYota4x4

iTrader: (5)

Hey man, .... FIRST OF ALL.... <<<< YOUR DOG DID IT! hehehe.. jk, couldn't resist with that cool pic you got up! hahaha.

Anyway, my experience on the same thing was an alternator wire that comes up out of the harness had rubbed(on the engine mount or something, can't remember), then shorted out, 2 times, before I found it. (I'm assuming you mean the 80A fuse, right?) I shortened that wire about 2 inches to get all fresh wire running, soldered it together, heat shrink, heavy duty liquid electrical tape.... VOILA, never blew again.

I've heard of shorts in the driver side kick panel causing this(one time due to corrosion and arcing thereafter).

Mechanic is saying what, the alternator is surging HIGHER output than 80A? OR, .... just something is fubar in it?

Terrys87

iTrader: (1)

When mine kept blowing it was on the drivers side of the tranny on the reverse light plug, just under the protective sleeve. I got a pic on my 88s build and where it is listed. It is a fairly common problem.

humboldtMUD

my dog would never, she'd get a harsh woopen j/k

terry are you talking about the backup switch that goes into the tcase? was it shorting inside or just the wire was rubbing the tcase?

chef i am not talking about the 80 amp charge fuse, that has not blown. is that what was blowing on yours?

i was talking about getting a napa 80 amp output alt, a upgrade from the 60 amp one i have.

my buddy was saying it could be something like the the diode trio failing and putting out a/c or like you said something fubar. he wasnt real convinced that was the prob, but i kind of wanted to upgrade anyhow.

i think my 4runner is just addicted to fuses. seems every time im getting beer at the market im getting fuses for my runner too

humboldtMUD

so i opted out of getting a new alt, i really dont think thats the problem. put all new grounds and it still blew. i did however notice that it went out twice when i put the blinkers on. i took them apart and everything seems to be in order. a while ago (due to a aftermarket bumper) i put smaller bulbs in the front and drilled a hole on the inside of the parking lamp housing, being a smaller bulb the blinkers always blink fast, and one of the small bulbs isnt working even though the filament seems to be intact. dont see how this could have anything to do with the engine fuse blowing, but i took the bulb out. see what happens

anyone have the engine fuse go out due to the turn signal?

ChefYota4x4

iTrader: (5)

Never happened to me(turn signal chain reaction, I mean! lol)...

Ahhh, ok, sorry bout that, regarding thinking it was the charge fuse... My bad. Wow...... gotta be a way to track back that short, right?(like using a meter that will hold a surge reading or something like that, ya know?)

humboldtMUD

i dont know, like i said it -was- a random short but last night i was mobbing around and got it to blow right when i put the right turn signal on(put it on just to see if it would do it)! put a new fuse in and did it again and bam, poped again, so i know its somewhere related to that. i may fix today but will probably just drink beer and go to the river and not use my signals. i will post when i figure, and i will ha, out what the problem is.

ChefYota4x4

iTrader: (5)

AH HAHHHHHHH! Ok, I need to look(not sure if I'll find it, to be honest)... But I KNOW this is not THAT uncommon. There is a cluster of wiring in the steering column that CAN get, well, 'wound'... Each time you turn the wheel, once this wire get's 'OUT OF PLACE(?)', it arcs and causes lights to blow out, etc. YOUR situation sounds different, to some degree... BUT, could definitely be a similar issue, especially considering all the ignition wires in there, etc. The turn signal harness(also includes the wipers, etc.) is all connected, right? Since it's happening when you turn the lights, only(not turning the wheel)... Sounds like you were on to something with the "changed some lighting up front"(signals, right?)... "smaller bulbs", etc., is what you were speaking of. MAYBE in that process you've installed it leaving something 'raw'?(or at least it BECAME that way).

I'm sure you're thinking/have thought of most of this... But I would track it back from the column. Hook up to the grounds of the signal and see if it's surging/showing continuity/AT the ground wire(maybe even test the full circuit for that signal stuff and see if it's reading '12.25V' when it's supposed to be 4V or something?). Can you trace that wiring loom from the signals you did, back to the lever assembly on the column? Just make sure nothing is exposed, then you could pinpoint RIGHT AT the lights/light assembly themselves?

PS> My buddy had some strange issue like this and it was TONS of corrosion behind his driver side kick panel fuse panel. It rotted and the wire fell out of the pins and was grounding on something(wasn't his signal, I don't think, but something to do with the IGN switch.

Just throwing some lob balls of 'guessville' out there! lol.

humboldtMUD

thanks for all the info chef. well today it isnt blowing no matter what i do...i took the cowling off the ignition and everything seems to be in order. the harness checks out good. i have continuity at the grounds. i dont see any visible flaws with the wiring... im just going to have to keep looking through the system. this rigs wiring is pretty good, no corrosion going on really anywhere

Terrys87

iTrader: (1)

Post #343 was what was causing mine. Just under the sleeve. Link.. https://www.yotatech.com/forums/f199...9/index14.html

ChefYota4x4

iTrader: (5)

My pleasure.... and, "No corrosion going on really anywhere in the wiring harness"....>> ONE good thing about MOST areas of CALIF. living! lol.

ChefYota4x4

iTrader: (5)

PS> What I was mentioning in the 'looking for voltage' was to check all the wiring involved in the column and see if anything is 'surging' or 'getting power' when it's not supposed to. Obviously, like with most gremlins, ....THEY FREAKIN DISAPPEAR as soon as you bring it in to have it checked! lol.

I really wonder if moisture has gotten into something crucial or if there is SOME raw wire that is touching ground and ONLY get's current when you 'engage' the signal lever/switched power wire meets ground=POOF! lol.

ChefYota4x4

iTrader: (5)

OH, and whatever 'TERRY', above, mentions..... Trust me, he's a bit of a guru with having taken these apart to the bare frame, put back together/hunting down gremlins, etc. I would at least check into whatever he's posted there

humboldtMUD

thanks terry, my back up switch is def not touching the tranny anywhere and the sleeve is intact.

everything involved with the turn signal system is all 12v and wasnt surging or anything when i put my meter on it.

i wish it would just get really bad so i can more easily find the prob, which is weird because it was yesterday, but i was on the hill and couldnt do any trouble shooting. it was blowing the fuse every time i put the right signal on. i went through like 4 fuses making sure it would do it.