Electrical system toast?

Hi all,

I have an '08 Tacoma and one of my kids left a light on in the truck...battery dies. No big deal, neighbor brings over a jumper kit to help, and before I noticed what he was doing he hooked up the + to the - terminal.

Now my truck won't turn over, A/C, power windows, clock, etc...won't function.

I checked the fuses and only found the radio fuse blown.

Am I totally screwed? Could it be a fusible link, circuit breaker or something like the ECU?

Any help is much appreciated...

Thanks,

Mike

 

... So you have ZERO power? Nothing functions at all?

 

Replace the battery
Check ALL the fuses. Under the hood and dash to ensure everything is working.
Should have power after that.

 

Agreed, Sounds like your battery is fried

 

Limited power...some dash lights work, but random lights like 4WD are on for no reason.

Horn works, door open sensor works. That's about it.

 

It may be the battery but even with the correct jumpers on, I still don't get power to a majority of the systems. Checked all the fuses and replaced the few that were blown...no improvement.

 

I would try battery and fuses before you get into anything crazy, like Aw9d said, that should do it.

 

Well if the incorrect jumpers were used too long, it probably fried the battery, meaning it wouldn't work even with the correct jumpers

 

To fully toast an electrical system is pretty hard to do. Toasting parts of it is easy.

You may have fried your ECU. But other functions of the truck should still work that are not controlled by the computer.

If you fully fried the entire electrical system, you'd smell it.

Take the battery to an autoparts store and test it. I bet its fried.

 

Thanks all,

I will start easy and progress from there.

Needs a new battery anyway so I will start with that.

 

I'd say your electrical system is fine. What usually happens when a battery it connected wrong, it blows out 1 or more of the fusible links. Check them all, very carefully.

I bet one is blown, as well as some of the smaller blade style ones.

 

Due to jumping it on the incorrect terminals, I bet least one or more cells in the battery have gone into a reversed polarity condition, frying the battery. You can check your existing battery voltage, but If I were a betting man, I'd say its shot. Replace the battery and check all the fuses you can find, like Aw9d and 1MK said.

If that doesn't work... You may be looking at a bad ECU, but I highly doubt it because, as said before, that can be pretty tough to do, especially off a jumper kit and not a direct car to car jump.

You are getting some dash lights and other power, so I doubt its the ECU, plus ECUs usually have a fault mode to save them from that.


I think you have a plan now though, start with the lowest common denominator and work up from there.

Best of luck!

 

And also, put your own cables on in the future.

 

I have noticed a lot of the new jumpers and cables have cross protection but still I have to wonder how people even do this. You have two choices when doing this and if you get it wrong I have to wonder where your head is.

But like everyone else I would say it is likely fine and just a shorted battery.

 

Thanks all...yeah my neighbor is like 90, lesson learned, don't let other people touch your truck!

I thought putting cables on was dummy proof.

 

Start with checking the 120/140A ALT fusible link. Bet it's blown.

 

Check highlighted

 

^^^Boom!^^^

 

Extremely helpful, many thanks!

Off to autozone.

 

Status update: 140a at fuse was blown, and a hand full of others. Replaced all and the battery, and it fired right up!

The only remaining issue is the E brake sensor and ABS light are illuminated. Is that an open circuit I missed or something else?

Thanks again, saved me a tow!

Mike