(Gen 2 Prius) Shorted rear wiper power and now I have no power to any electronics on the rear hatch

To make a long story short I tried to wire an aftermarket back up camera to my rear hatch and ended up shorting something and now I have no power to anything on the hatch.

I tried splicing the ~13V wires from the rear wiper to connect to my backup camera. When I turned on the car, the camera did not send a signal. Suspecting a polarity issue, I switched the + and - wires going to the camera and restarted the car, which resulted in various dashboard warning lights and still no camera signal. I used a multimeter to check the power from the wires, but there was no voltage. Further, I noticed a complete lack of power to any other electrical systems in the hatch. Thinking a fuse might have blown, I checked for continuity in both the interior and exterior fuse blocks without finding any faults. Visually inspecting the fuses I thought might be involved also showed no issues. Finally, I disassembled the dashboard and examined the body control unit fuses on the driver’s side; neither the 30-amp nor the 40-amp fuses were blown.

Does anyone have any ideas?

 

I got my hands on the the wiring diagram for the car took a look at the hatch area. I noticed there were no fuses between my splice point and the body ECU, which leads me to believe I damaged the ECU. I tested all the electronic components in the hatch, from the hatch release motor to the lights, and everything appeared functional. I ordered a replacement body ECU so I'm hoping that fixes the issue.

 

1. Have disconnected the nonsense

2. I needed 12v for the camera that would turn on when the car turned on and I deleted the rear wiper motor so it made sense. But moving forward I'm definitely going to just do accessories right with a relay, fusible links, and a distribution block that takes power straight from the battery. This was particular job was admittedly very poorly done by my standards.

3. This is where I spliced:




Link -

This is what it would look like on the wiring diagram



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Like I said earlier, both the relevant fuses were not blown. After looking at the schematics, I wonder if the J34 module is damaged. Here is everything that doesn't work on my car:




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But its just a junction connection, I don't really see how that would cause my issues unless I accidentally unplugged it while I was working. Even then, that wouldn't explain the weirdness on the dash while shorting and the fact that I was getting power before I shorted and not after.

Here's another image of the diagram



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All roads seem to lead to the body ECU so I think I might've damaged that as well. I'll check the junction connection tomorrow and report back.

 

I couldn't wait and I went to check on the J34 plug and found it was unplugged. I plugged it back in and only my middle brake light came back on. Everything else on the hatch did not work. I'll have to look into it tomorrow.

 

An update:



Good news is I fixed the license place light. Only the left light is on but I'm just guessing the right one is burnt out. I'll check tomorrow.

I was checking continuity today and my inspection lead me to the J31 junction box. This box supplies ~12v to the hatch electronics. I inspected it and tested it with my multimeter. I took off the cap and it looked like it wasn't broken so I put it back and I somehow got power back to my license plate lights and my rear wiper motor. Not sure how that happened but whatever.

My hatch still doesn't open though.





I checked my continuity here and I'll do more testing tomorrow

* I seem to have some issues getting my images to display so I uploaded them below

 

Update - It was the relay between the luggage compartment courtesy switch (the switch that tells if your hatch is all the way closed or not) and the body ECU. Replaced it and now I have full functionality back.

 

So I finished my project today and ended up doing it the right way. I have a relay with a fuse that supplies power to a screw terminal block when the car turns on. I’m gonna use this to power all my aftermarket accessories. I have some water temp dials along with heated seats I need to wire to.

To anyone looking to do this sort of project, please do it right the first time and consult the wiring diagrams.