The words of the morning have been Frustration and Ease.
First the frustration.
When I inspected this Prius at the auction lot, I could not get the hatch open. Now, this is a point of confusion on Prius anyway. You see, the latch to the hatch is one of those pressure sensitive powered push button type switches protected by the overhang just above the lisence plate. The key issue is that if your Prius battery is dead then you have no ability to activate the power switch to open the hatch. And, oh yeah, the battery is in the trunk.
There is a jumper point under the hood. My usual method is to hook the jumper pack up to the jumper point and then you have enough power to work the switch. At ther yard, this did not work. I was so diligent that I then folded the seat and made the major wrangling manuver to get my jumper pack hooked to the actual battery in the actual cargo area. Still, the hatch would not open. And, still the car would not start.
I then made the trek back out to the parking lot of the yard, to my car when in the car I had the back-up plan. In case the jumper wasn't enough, in the car, in an Ikea bag, I had a real car battery and a set of real jumper cables. I wrangled back through the cargo hold again and hooked up the real battery. STILL, the hatch would not open.
Pic from the yard of big battery.
However, the real battery was enough to get the car started...or so I thought. What I mean is that, yes, the car started but in retrospect the large battery may have been coincidence to the actual starting. You see, my other Prius and this Prius have those proximity keys. The type where if the key is present in the car, you just hit a button to start. I kept hooking up jumper cables and trying the button to no avail. But...if the small battery in the key fob is soooo dead then you actually have to insert the fob into a slot. It wasn't until I had that large battery hooked up that I actually tried that fob-in-slot approach.
Later, after having the car home, I did confirm that the fob battery was absolutely dead. A fresh battery and the fob now works exactly as intended. The pictures of this car on IAA we date stamped Dec 26. I bought the car nearly 3 months later and the coldest, harshest 3 months later possible in this harsh winter. It comes as no surprise that all batteries were dead or weak.
But, still not hatch opening.
With the car battery charged and car running and all working well, if I go back to the hatch latch I can hear electricity running the release motor but nothing is opening. The manual and internet tells me that there is a hidden manual lever way up in there to pop the hatch. This doesn't work either.
I need to stress that there doesn't seem to be any rear body distortion or "out of square-ness" about the hatch that should be the reason for it not opening.
So, back at home today, I have P1 parked next to P3. I start breaking down P1 to better understand this hatch latch. First, I access this special hidden manual release that is hidden. Sure, enough, that works perfectly on P1. I'm analyzing the hack out of P1 and removing trim that I can not remove on P3 due to the door being closed. It seems that the hidden latch is dead on P3. What I am trying to see is what other parts are supposed to move when that latch is tugged upon. To exasperate the frustration, I am viewing parts from the top on P1 and accessing them from below on P3. But, not just below, I have crawled into the cargo hold, with my ear resting on a spare tire. My torso is contoured in un-natural ways. Furthermore, what I see as "push down" on P1 is then "push up" on P3. Yet further, I am trying to balance a flash light and a tool, in one hand. The need to push is hard in this leverage position.
I bet I climbed in and out of that trunk 5 times trying to go back to P1 one more time to see again how it works, etc. The whole thing had similarities to building a ship in a bottle. I could see to get my tool to the spot but then to push on the spot, I couldn't really see what was happening. On one try, it magically happened and the latch freed. I quickly jammed my screw driver in the way to act as a preventer from the hatch latching again.
This pic "after" with them now both open.
More "after" pics of the latch. Most of this would have ben shielded by plastic trim when still closed.
Here are some zoom pics of what I found. The bar is powered. It si supposed to ride on the white nylon a and as the bar moves it forces the round white nylon coated roller to lift which trips the latch. However, the bar was not riding on the white nylon covered roller any more. The bar had jumped to in front of the roller. In hind sight, the bar was moving (and I could hear that happening) but the movement of the bar was not making contact with the roller.
Here is the "fixed" picture with the bar once again riding on the roller.
Was this a product of the impact? It's possible.
Best part, it was a zero dollar fix! The hatch and latch are 100% back in business.