Difficulty jumpstarting from the front/engine.

one thing is that the jump terminal only has metal on one side. so you have to make sure your connecting the clamp properly.
another could be that a bad cell in the 12v is causing interference, and it would have to be disconnected.

 

Some clamps may not conduct well from both sides of the jaws, so make sure you connect the side with the actual wire to the metal side of the jump terminal in the fuse box.

 

you can disconnect the battery positive, put the clamps on the jumpers, and measure the voltage at the back.

 

I thought the "jump start terminal" was actually the 12 volt connection for the inverter 12 volt output to the main fuse block and not for jump starting. I could be wrong, but I remember this connection when I replaced my inverter.

 

BTW, if you have to jump start the prius battery more than once, buy a new battery. Doing it wrong costs at least $150 and as much as $4000.

amazon.com/ACDelco-ACDB24R-Advantage-Automotive-Battery/dp/B010GKJ8F6

 

the jump point is under the flip up red cap, inside the fuse box under the hood. it is connected directly to the positive cable in the back. the manual shows it for easy jumpstarting when the hatch won't open, or the front of the car is more accessible.

 

The battery died while in a mall parking lot. A tech from Sears attempted to start it using the front jump access. All the portable jump starter did was make the dome light glow a bit. Later someone attached jumper cables from his car battery to the Prius battery and the car was ready to run instantly. It takes a couple of minutes to crawl to the hatch inside release, but I think jumping directly to the battery works best. The battery posts are soft, so the jumper cables make a good contact.

 

So we have to let the Gen 2 sit for about 3 weeks. I'm a little worried about the HV battery and was hoping to talk my brother-in-law into starting it once a week, but it didn't sound like that was going to happen. (It's the wife's car now, so if it dies from non-use, she will have her brother to blame.) ;-) At the very least, I decided to do what I could to preserve the 12V. As I had done on a previous occasion, I disconnected the battery ground cable in the hatch. Before I did that, I removed my jump kit from the back, hoping to save the crawl through the back 3 weeks from now. I had read prior posts saying hooking up a jump kit to the jump points under the hood should enable the power locks, but when I tried to do that, I got nothing. (No interior lights and no power locks). I did see a solid green light on the jump kit telling me that everything was hooked up correctly. Has this method of avoiding the crawl been proven to work by anyone? Is this just an urban myth?

 

To answer my own question, a jump kit will allow you to power the locks and open the trunk. I was all prepared to crawl in behind the rear seats this morning, but decided to give the jump kit another try and after hooking it up, lo and behold, the interior lights came on, the power locks responded to my push of the switch on the driver's door and the trunk lid opened when I squeezed the very worn rubber latch handle. I was doubting this would work with the 12V battery completely disconnected, thinking that probably the power locks electrical circuit would be interrupted without both cables attached to the battery. It appears another power source connected to the under hood jump points creates a new circuit. Hallelujah! I'm not sure why it didn't work when I tried it before we left. Possibly I was not getting a good enough connection at the jump points. (Please correct me if my explanation or reasoning is faulty).

 

Separate the jaws of your cable clamp with a piece of wood, then check for continuity from one side to the other, with a multi-meter in ohms or continuity mode.

(Just realized that question is pretty old.)