Tonight I was trying to install a Optima Yellow top battery into my 4 runner. I removed the old battery and while talking on the phone to a friend I tried to install the new battery. I wasn't paying attention and installed the Optima backwards. I connected the + to the - terminal and vise versa. I saw a spark but thought nothing of it at the time. I went to check things out and I have no power whats so ever in the cab. The only fuse that I can see that is blown is the 100 amp alternator fuse. Is this the location of my power problem and how easy is this to replace? It is dark out and I don't have a garage so I am struggling to locate any other issues. But while trying to remove the fuse the two legs seperated from the fuse housing and stayed in the fuse box while the cover came out. What do I do now? I am new to electrical issues and am in need of help. Any info would be greatly appreciated. Do I need to look elsewhere for issues as well? Could I have fryed the new battery?

 

that 100 amp fust is the main power to the whole truck. Replace that fuse, all should be good...and thank your lucky stars you didn't break anything else.

BTW That fuse does not pull out the top. It slides out the bottom, and is actually bolted to the wiring with 10mm and 8mm (wrench size) bolts. DONT try to pry it out the top, it will only damage your fuse block. You have the press a clip aside, then slide it out the bottom.

 

Thanks for the info. Is it difficult to get to the underside of the fuse block? Do I need to worry about anything else when I go to remove the top of the fuse block? I have to fly out of town tomorrow for the weekend and will not return until sunday late night. Can I get this fuse at any auto parts store or do I need to get it from toyota? Could I have damaged the Optima battery? I also read that if the battery is disconnected for to long that there could be an issue with the air bag sensor or something to do with the air bags not functioning correctly. Could this be an issue I will have to deal with?

 

lemme stop for a sec....what year is your 4runner? Im talking first gen heh. I have 4runner on the brain.

Either way, you DO have to press it down and out of the block regardless of the year it is, and its attached with bolts, no matter what year it is.

 

Sorry i should have stated that. It is a 98 4runner.

 

My brother made this same mistake with my dad's 95 Runner. I ended up replacing the fuse you are talking about.

Anyway, after replacing the fuse and getting the truck to start, the two map lights under the rear view don't come on, the radio doesn't come on, and the dome light doesn't come on. All of which blows cause I hate electrical. I hope this didn't happen to you after fixing the starting issue.

 

Well I got the 100 amp fuse replaced yesterday before I had to fly out of town for a wedding. The dash lights came on but that seems to be it. I did not try to start the motor just because I have a lot of other stuff in pieces right now in the engine bay. However, my dome light doesn't work and my electric door locks weren't working. This was all I had time to check out before I had to go. My alarm did work but it wouldn't run the locks either. Could this be due to a fuse or a computer problem? I will hopefully have some more time the first of next week when I get back in town. Hopefully it is just fuses and not something else. Any info on this would be greatly appreciated. Thanks for all the replies.

 

I would guess you blew some other fueses... there is also a fuse block inside the truck, check there.

 

Well I checked all the fuses and only found 1 that was blown. It works with the dome lights and continues to blow fuses. There has to be a short somewhere. I have no automatic door locks and my radio doesn't seem to work. I also get two clicks from the passenger side engine compartment when I turn the ignition to the farthest point before it turns over. I have never noticed this before. I am begining to think I need to take this to a mechanic but I am afraid of the charges. Electrical issues are never cheap from my experiences. Anyone have any ideas.

 

I can't remember, but do these trucks run fusable links too? If so, check those.

Edit. Sorry, I didn't realize this thread was over a year old.

 

Ouch, that one sounds expensive! I blew the 100 amp on my 2000 Camry a little while back and wanted to clear up a few things with the replacement, this seems as good a place as any... Took way longer than it should have thanks to crap write-ups like the one from 2carpros everyone online (outside Yotatech of course!) seems to quote. Should have just forced the clip as was my first intention, and DeathCougar's suggestion, than trying to decipher that WU. So hopefully this will save someone some time.

I was trying to replace the alt belt at 1130PM in my GFs driveway so things were a little rushed. Doing just the belt, I didn't bother to disconnect the battery, but the tensioner was rusted solid so I snapped the mount bolt off in the alternator when trying to loosen it. Not thinking, I went to pull the whole alt so I could drive home at least and arced out my positive wire on the alt casing. Car started and drove but had no blinkers, windows, door locks, etc... Took a while to even find the fuse that popped, it was broken off to the side, and didn't blacken the plastic. I was thinking I shorted a relay for a while, but easy enough to fix once realized.

Contrary to a lot of info out there, it wasn't necessary to take the fuse box off or disconnect any lower connections. Just jammed a screwdriver in the 4 latch clips on the middle portion of my engine fuse box and popped it off, and even that might not have been necessary. The 100 amp box was sticky but using needlenose to separate the 2 clips while pulling the box it came up.





Fuse just unbolts, an 8 and 10 mm on sides. Also, someone had written this was a dealer part, which made sense, but I did find one in the local parts store for $2.5 when the dealer wanted $10.

Still had to drill and tap the alternator bolt, sized up to a 10mm, reamed the adjuster track with a long 3/8 and a flat file, redrilled the adjuster block hole out to 7/16, and replaced the 8mm adjuster bolt. Lot of anti-seize this time around!