2007 Prius, Hv Battery issues after replacing 12 volt

my first post & I have a car that powers up, but won't move.
I have been working on cars for more then 40 years, but this is my 1st hybrid.
I bought this 2007 Prius in November & noticed that the lights were dim pre-start up. I had a busy Nov. - Dec. but
I did check the 12v voltage and it was holding 10 volts. Car off, that's not good. So I replaced the 12 volt battery last night with an Optima 46B24R. I used a 12v 7amh gel cell attached to the jump start terminal to hold memory, work door locks, etc... I had the key fob disable button pushed in too.

There were no shorts or sparks of any kind, at any point.
I know how to work with high voltage having tied in 3 phase 208 ac hundreds of times.

Since I had the rear floor out & saw no evidence that the HV battery had ever been serviced. I pulled the rear seat and deck over the HV batt. I wanted to check its voltage. I did watch a youtube video on Sat. on replacing it.
So I pulled the orange safety plug. And took off the two left side cover plates, to get access to the relays. I took off
the plastic covers & checked with the meter to see if one side was grounded to the car. It is not. Then I put the orange plug back in and checked the voltage, 218.4 volts. Better then I expected Maybe some of my low gas mileage was do to a bad 12 volt battery?

I then pulled the orange plug and marked plus & minus with a sharpy. Put the plastic covers back in place. Then replaced the metal covers, left side interior panel, etc. Then replaced the orange plug. I then tried to start her up. All the warning lights, but the low tire air & maintenance lights stayed on. She won't go into drive or reverse.

I searched the net & your forum. After getting some ideas I checked the fusible links in the fuse compartment under the hood. And at the battery, all good. I then checked every fuse in the car, both under the hood & dash. also all good. I then thought maybe I put the orange plug back in wrong? so I pulled it and tried to start. Exact same result. I checked the orange plug for continuity, in case it has a fusible link inside, also good. I have pulled the left rear side panel off & the cover plates back off the HV battery. with the orange plug in I get 218.4v at the relays. So that is ok. I haven't yet checked for voltage on the other side of the relays with the car on. But I bet there is none.

This is a picture of my warnings.

 

Oh, forgot to add no codes thrown.

 

bisco,
I think so, it slides onto the plastic nubs. Then the handle goes up as it slides in. There is power to the battery side of the relays with it in. There isn't when its pulled.

 

Thank You dolj,
I had not locked it. The guy on youtube didn't either & I swear it wasn't when I removed it. And the green factory seal tape was already broken. So someone had been in there before. I powered up the car & same symptoms.

I then powered it off & tried again & all error lights went out but the red triangle of death. The engine came on for a couple of minutes. Then shut off (climate control off), its 35f here. I then checked the HV battery voltage. It showed 230 volts on the drivers side of the relays. So no idea why it thinks there is a HV battery problem. It will go into drive now! Thank You!

 

Thanks Patrick, it threw no codes, the 2 times I checked.
After I made my last post, I finished my morning ruteen. Then I went back out to the car. It started with no warnings. So I put it all back together. And ran some errands with no problems.

BTW: She has 158447 miles, would a HV battery reconditioning help it last longer in battery mode. As in crawling along in traffic. At less the 19mph, she can only go about 12 minutes before the engine has to come on. This is with climate control off.