Battery Terminals Installed Backwards?

[SirSam]

Does anyone know what direct effect it would have on the car if you put the Positive lead car wires on the batteries Negative terminal, and the cars Negative lead on the batteries Positive terminal? What fuses would blow or what devices would be effected? Thanks!

[mehullica]

You'll blow a couple high amp fuses under the hood. A few low amp fuses in the car.

[soarer_bang]

worst case ur ECU can *BLEEP* up~ so check it out.. but it's not gonna happen that easy~ ^^ only few fuses will blown .. so don't worry~

[MitchB]

Hopefully, the fuses blow before the alternator diodes short and kill your alternator.

I'd worry.

[monarch]

I did that once by accident on an old '73 Toyota pickup. Within seconds the battery cables caught on fire!! Fortunately I had a fire extinguisher close at hand and put the fire out before any serious damage was done.

I was also fortunate that an old truck like that didn't have any computers or complicated electronics that could have been destroyed.

[SirSam]

So far it just looks like the Fusible Link, the 7.5a alt sensing fuse, and the 20a radio fuse blew. I'll be replacing the fusible link tonight, it was bolted into the fuse box, very interesting. I'll let you know if I was blessed & thats all I blew. My Alternator was already bad because of PSP leaking. Thats why I was replacing battery so I could drive it home, go figure i bought an inverted terminal battery, well thats a first and to never happen again.(wrong battery that is) It was late & i was tired. Had to special order 150a fusible link from dealer, about $20.

[jxc]

So far it just looks like the Fusible Link, the 7.5a alt sensing fuse, and the 20a radio fuse blew. I'll be replacing the fusible link tonight, it was bolted into the fuse box, very interesting. I'll let you know if I was blessed & thats all I blew. My Alternator was already bad because of PSP leaking. Thats why I was replacing battery so I could drive it home, go figure i bought an inverted terminal battery, well thats a first and to never happen again.(wrong battery that is) It was late & i was tired. Had to special order 150a fusible link from dealer, about $20.

Thanks for posting this follow up. It saved me a lot of time. A little more information to help the next person:

The 150A fuse can be ordered from either a Lexus dealership or a Toyota dealership(it doesn't seem like something that is kept in stock). It's part #9098208272.

1. Once you take the black cover off the fuse panel under the hood you will have to remove the bolt beneath the red "+" clip, unclip the yellow colored fuse block from the adjacent fuse block and pull it out some before you can unscrew the 150a fuse. There is a screw on either side of the fuse block holding the 150a fuse in place.
2. A local auto parts store will likely have a 120A fuse on the shelf that can be used temporarily while you wait for your 150a to arrive. The 120a may need a little modification as the slots the bolts pass through may not be big enough. They can be snipped or ground to a larger size.
3. The 7.5a alt sensing fuse and the 20a radio fuse SirSam mentions is also in the panel that contains the 150a. Read the underside of the panel cover for their location. You may also find some replacement fuses there that have been thoughtfully provided by Lexus.