I have a 2012 Toyota 86 and I accidentally put the negative on the positive and a spark went off and I blew the fuse on the battery.

Image below. Look at the little red line that's where the fuse broke.

I have the spare part ordered and will be here in 3 days.


I need my car for the weekend. Is it ok if reconnect the fuse using copper wire where the red line is in the image, and connect the battery properly as a temporary fix until the replacement part arrives?

enter image description here

  • can you see where that cable goes? Straight to the alternator perhaps? Can you tell what the fuse rating is? (We can see the other one is 80 amp..)
    – agentp
    Jan 5, 2018 at 17:03
  • Uber/Lyft in the interim. It's cheaper than frying your ECM or worse. Jan 5, 2018 at 19:09
  • @agentip it's 80amp
    – joeyk16
    Jan 5, 2018 at 23:05

2 Answers 2


That would work, but it's a very dangerous solution. The fuse exists in the circuit as a safety mechanism. If the circuit is flowing more power than it can safely handle, the fuse self destructs and stops the flow of energy. If the fuse is replaced with something that continues to handle an unsafe load, bad things can happen. Wires can melt, get red hot, and light things on fire.

I wouldn't really even recommend doing that for a small auxiliary circuit. For the main fuse like that, you're asking for disaster.

  • 2
    Totally agree, unless you need to escape a group of brain eating zombies I'd recommend against it.
    – GdD
    Jan 5, 2018 at 14:24

It was stated that the fuse blew for a known, transient event, so the prospect of re-incurring a fatal scenario is not a serious one. Nonetheless, I would be inclined to add the cost of a car rental to that of the spare part on order, against any possibility that the computer could be harmed. As for that "other fuse," it appears to be not a voltage limiting fuse but a load limiter.

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .