Reverse Polarity Jump Start - Gen3 Prius wont Start

Well, the problem will be when the OP finds that link is dead. Then I think he will have to remove the relay/fuse box for access to the bottom of that link.

Or, is it possible that if he removes the bolt at Terminal A, that is the other end of the fuse link which can be snaked through?

 

I think you are right. Terminal A is where cable from Inverter DC/DC connects. The 1E connection goes back to the 12V battery. So the Fusible Link looks like it is between A and 1E, which is probably under the relay/fuse box as you say.

The Repair Manual just says if Fusible Link is open, to replace it but does not show how.

 

Find attached a picture of the relay/fuse box.

It looks like the metal piece under the bolted connection could be part of the fusible link but I cannot tell without removing the bolt.

The white cable to the right that plugs in goes to the 12V battery.

The cable under the bolt goes to the Inverter module and connects to the DC/DC circuit.

 

Well, most likely I believe the problem is a burnt fusible link. It can be either the engine compartment, kick panel or the rear positive terminal, but the positive terminal looks good, then I would check the other 2. I think it's bolted down as well.

 

Or maybe finds the fusible links are all OK, but a few much more expensive components are dead.

 

let's hope not.

 

No doubt complete coincidence if the inverter is fried immediately after a jump start.

Liar, liar, pants on fire.

 

Cautionary tales about being REALLY sure to not reverse jumper cables aside:

If it's the case that a cable reversal can destroy $1000's of fragile electronics, is Toyota remiss? Is is possible for them, at reasonable cost and complexity, to protect against this?

 

good question. is it possible for them to keep the 12v from draining if you leave the dome light on?

 

The inverter frequently will fail with a reversed polarity jumpstart because the inverter output transistors will be shorted out when negative voltage is applied to the positive battery terminal. To protect against that would require an inline diode in the inverter output which can withstand 125A current flow. Further, having the diode inline would reduce the output voltage by 0.7V. Hence this would not be an elegant solution.

 

Hope you find a replacement fuse and that solves your problem. If nothing else, we're getting an idea of why some repairs cost so much. I have a Dodge truck with a $28 heater part that costs over $600 in labor to replace. I had it replaced once and it broke again 18 months later. Fortunately, I live in Phoenix, so I may never replace it again. Good luck!

 

Sergey, strong work! thanks for the pictures. i'm sure this will help some other people down the road.

 

Please take and post a photo of the fuse after it has been removed from its socket.

 

Ditto to the above.

Thanks Sergey.

 

this may be the first time this has been diy'ed. great job. and thanks to all who helped, especially jd.

 

So I was right about the fuseable link good find sergey

 

Sorry to hear about the battery issue; I hope you get it resolved soon. Just my opinion, probably less grief to just bite the bullet and take it to the dealership. You could spend lots of time and effort trying to troubleshoot and probably still end up having to take it to the dealership. Keep us posted on the outcome and best of luck with it.