Weird electrical? issue after dead battery. Horn stays on, etc. FIXED: BLOWN MAIN FUSIBLE LINK

Hi all. First post for my '08 5.7. Weird issue that I haven't been able to solve yet with internet research:

My daughter left the key in ACC position overnight and killed the battery. In the morning we tried a quick jump start. No cranking, but the horn went on when I turned the key and STAYED on until I removed the key. Tried once more and same thing happened. We were late so I hooked up the charger and took another vehicle for the day.

Now that the battery is charged, the engine cranks but doesn't start. In fact it cranks for 5-6 seconds even when I let go of the key...I've read that's normal. Now for the weird part. Many electrical functions of the vehicle don't work, including radio, power windows and door locks, ODB2 port, wipers. However the headlights, hazard lights, horn, dome light work fine. I checked the fuses for the non-working items and found them all good.

I have today to work on it with an extra set of hands/eyes, but any input from any of you out there would be greatly appreciated. Thanks!

 

Thanks Ron. The battery is only 8 months old, and cranks the engine easily so I think it's ok. I have tried the ECM reboot by removing both battery cables and holding them together for 10 seconds as I read to do, but no success. I was hoping my ODB2 code reader would help, but it can't link to the computer because the truck's port is dead/no power.

 

Good idea, but sadly not the case. The fob makes the truck beep when locking/unlocking, but doesn't actually activate the locks, presumably due to the lack of power to them. The anti-theft light by the clock flashes as it should when no key is in the ignition, and goes out as soon as I insert the key. I have now checked all fuses under the dash and all are good (replaced a few to test). It appears that every circuit that runs through the fuse panel under the dash is not working, except that the instrument panel lights all work despite being on a circuit handled by this panel. Weird!

 

I've been reading and reading, and I'm starting to think I may have crossed the cables when I tried to jump start it. Of course, I don't think I'd ever do that since I've jumped vehicles dozens of times but I read a thread about a guy that put a new battery in that had opposite terminals and his symptoms sound like mine. The horn stayed on, he said. My horn only came on when I tried to start it though, not when I hooked up the cables. Anyways, just more info for anybody reading this...

 

Did you look at the fuse box under the hood? Sound like you may have poped one of the big ones.

 

Yes hunter, I found 3 fuses blown: 2 10amp having to do with the fuel injection and one 15amp for the audio/nav/ent system. I now got it running, but still have no power to the other items. I need to determine if I blew a fusible link and/or the big 180amp fuse I'm reading about that's a pain to get to.

 

The items you have left not working should be handled by the fuse labeled RAD 2 7.5A located by driver left knee I believe. You are taking those little fuses out and checking them individually ?

 

Bubba, I don't have one labeled RAD 2 at the kick panel, just RAD 1 under the hood, which is a good fuse. My manual says the one labeled PANEL 7.5 (kickpanel) is for the audio system among other things. I have pulled all fuses at the kick panel and all are good. I can't detect power there with my volt meter (key on) like I do at the fuses under the hood, so I'm trying to figure where that interruption is. My best guess currently is the 150amp LH-J/B fuse. Thanks for any help.

 

What year is your truck?

 

Steve, it's an 08. 5.7
Definitely seems like the main fuse assembly from my research.
Dealer says the big 180 and 150 amp fuses are integrated into that assembly.

 

Do you have the owners manual in the truck? If so, go to page 595-597. It lists all the fuses and what they power. I am still thinking you blew one of the odd shaped fuses. Like #56,57. The 180 amp you mentioned is #62.

At least those are the numbers in my 08 5.7 manual

 

I have the same manual. Both 56 and 57 are good fuses.
Dealer says the fuses block for 60-65 is $47. Youtube says about an hour to replace. I'll try to test it beforehand with my voltmeter.

 

The book is deceiving. I went out and popped the hood at you are correct. Hopefully that will be it. From looking at the manual they looked like plug-ins

 

Any idea if you can tell visually if any in that block are popped?

 

Look thru the windows on the top of the block. Not straight down but towards the front side and the back side. You will see a metal plate that has a thin strip of metal - kinda like a fuse filament. I took a picture of mine but it is kinda crappy so I am not sure if it will help. Look in each window - front and back.

 

Here's a picture of my fuse #61 150amp that supplies pretty much everything at the fuse box under the dash. It sure looks good to me...what do you think?

 

You probably know this but all of the below is what fuse #61 covers according to Owners Manual...all those items are not working ?
Do you have access to a VOM(volt ohm meter) or cheap continuity tester. Hard to be 100% sure but the fuse does not appear to be blown from my couch.

 

Yep, all that stuff is out. Except I can start the truck and AM1 lists "starting system" as one of its circuits. I was thinking maybe it blows somewhere below, but seems to me the windows are for seeing if it's blown or not.

 

Always check a fuse,any fuse with a VOM or some kind of tester to be sure if it's good or bad. A blown fuse caused by a short will be black and there will be no doubt it's bad. But fuses can separate inside with such a small crack the naked eye can not see. You don't want to take it somewhere,like the Dealer and find out you simply had a bad fuse and be charged a hefty amount. Good luck.

 

Ok folks, it's all done...up and running again. Here is a picture of the burned fuse. It's in location 62 from the manual (ALT 180 A).
The fusible link/block cost $47 at my dealer, and it took me about 90 minutes to do the job. There were a couple Youtube videos that helped, but it was a bit of a pain getting all the clips around the fuse box undone. I ended up leaving the 2 on the driver's fender side clipped, and opening the fuse box like a door...enough to get this part out. Also, I took a hint from one of the videos and created a hole in the side of the fuse box in order to get to the 10mm bolt that attaches this part to the next series of fuses. Getting this fixed feels like redemption, since it had to be my crossing the jumper cables that caused this. From here on out, it'll be check twice, connect once for me. I hope this helps anyone down the line, and thanks to those of you that lent advice to me.

 

Those that say they've never made a similar mistake are fibbin. I'm confident you possibly learned more than just Sparky showing up by dealing with continuity and voltage checking.

 

Glad you got it back up and going. Look on the bright side. If you wouldn't have crossed the jumper cables you would not know how to change the link block

Everyone has been there before.

 

I am having this same exact issue with my '05 Sequoia. O'Reilly's sold me the wrong battery (even though I gave them my old one) and without realizing it, I connected the negative to the positive and the positive to the negative. Sparks flew and the horn went for an extended period of time until I disconnected..

I went back and installed the correct battery, but now the dash lights won't work and the car will start but not turn over. I think this is the same issue as the original poster.

Any idea on what fuse # for the '05 Sequoia? I am very novice at this (ex. 1 -I connected the battery this way), so any help would be appreciated!