Reverse polarity jump / Fried inverter / 2008 Prius

I own a 2008 prius. My auxiliary (12v) battery was going bad and I had to jump start my car. The friendly stranger helping me, put the cables on the wrong poles on his battery, and reverse polarity jumped my prius. All electrical systems down.
I towed it to the Toyota dealer (big mistake) and they started to take a look. Initially it is $150 for the inspection and first diagnostic. They found that obviously my main fuse was blown, along with two small fuses (rear lights and something else small).
This repair was $600, but they could not see if any further damage had been done without replacing these three fuses for $600. So I said ok (big mistake) and they replaced the fuses for a ridiculous $600. THEN they said they needed to do a second diagnostic, to see if the inverter was fried (the part that converts power between the 12v auxiliary battery and the High Voltage hybrid battery) and this diagnostic would be another $300.
After sensing a bad feeling, I told them to stop everything. After researching, I found that the inverter is going to be fried if you jump your prius with the polarity reversed, and the main fuse sometimes prevents this but generally only in a certain setting like shorting the battery in another way. But if you hook the cables up backwards and see sparks from the donor’s car, you’ve fried your inverter (especially if you see or smell any smoke, or any melted anything).
After calling Toyota back and asking if they could tell me if they thought the inverter was fried, they of course said they could not tell me without the second diagnostic to “open up” the inverter and look inside (as if they couldn’t see damage to it from just looking at the outside) and this like I said earlier would be $300. Making it a total of $900 to replace 3 fuses and tell me the inverter is fried. To replace an inverter in a prius at any dealership is $4,000 they also said, and that I can only have it done at a dealership. After already spending $600 for three fuses, I declined their advice, and got my prius the **** out.
I purchased a used good condition inverter off a parts website with a 1 year warranty for $170 and had a local mechanic install it for $550 out the door. BUT he also replaced my water pump for only an additional $200, something the dealership quotes as an $800 job (just to replace the water pump).
So instead of paying $4,900 to replace the inverter, and three fuses, I payed $750 to replace the inverter and the water pump. And the $600 to Toyota for three fuses and what should be a 30 second visual diagnostic on the fried inverter. This is something my new mechanic said he would have done for free, and only charged $60 for the parts cost of the three fuses.
Other than all of that, the people at Toyota are very professional and have very good customer service so it’s VERY VERY easy to accept what they say and take the advice they give. ONLY take free advice, and try to understand exactly what is happening and what is wrong or broken on your car so that you can research on your own, and decide if you can find a cheaper way. I think I got partly lucky (pun intended) that I found a guy to put in my used brought in part (inverter) because most places will say they don’t do that. But just keep looking until you find someone who will just do the job because it’s an easy $500 to charge for the labor (he charged two hours to take out the old inverter and another two to intall the one I brought). And compared to $4,000 that is a nice deal. Just make sure you are buying the right parts (part numbers, same year same model vehicle, etc.) and are certain that they are the issue that is occuring with your vehicle.

 

It is very sad and very ridiculous that Toyota has made this problem even possible, almost criminal seeming. Not to mention the price the dealerships charge for fixing this problem once it’s happened. But the fact that there is nothing preventing this problem is not an accident. It’s a money grab, and I’m sure it’s made Toyota so much money it makes me sick.

Speaking to a few of your points however, I believe it is very much a priuschat problem because I came here, when I felt a very bad deal offered/given to me by Toyota, and it helped me figure out what happened and what was actually damaged, without paying $300 for the Toyota diagnosis. Furthermore, after learning here what an inverter is (converts energy between the High Voltage hybrid battery and the 12v auxiliary battery), I also learned it is what gets fried from a reverse polarity jump start. That and a few fuses. Priuschat saved me that $300 diagnosis and subsequently about $4,000 for the entire fix, once I confirmed the inverter part number, bought my own used one with a warranty, and found an independent mechanic to perform the replacement. Also, I believe this is as good a solution to this problem as we’re gonna get. Hope this helps someone like the other posts about this on here helped me.

 

Lots of people accidentally hook the cables up wrong, or don’t even know how to jumpstart a car. Don’t shame these people, they need help. In my case, the donor’s battery was so coroded that he couldn’t see which terminal was positive or negative, and like an idiot, he just attached and boom, sparks. That quick, and I had a $4,000 plus fix. I managed to get it done for under $1,000, and that’s what this post is about.

 

By posting here.

 

I just explained how the donor’s battery had such corrosion that he couldn’t see the terminal markers and he accidentally connected the cables backwards. There are plenty of posts about this happening, and I am not telling people to connect their jumper cables correctly. I’m explaining the $4,000 that I saved after having this happen by doing everything that I wrote about in my OP and avoiding a dealership fix. So you’re out of line, stfu, and let this story help someone else, who might have unfortunately had this happen, from spending $4,000 when they might not need to.

 

By the way everyone,

Yes.

And I agree it’s near impossible to prevent accidents like this. Anyone SHOULD know how to jumpstart a car properly as well as know the consequences for hooking the cables up wrong for their particular car, BUT there’s not much you can do when it happens as an accident or because of an inexperienced donor/person is hooking up the cables. I’m just trying to help people save money on the repair in a worst case scenario where it fries the inverter. Dealership quotes it +$4,200. A good condition used inverter assembly is roughly $350.