Yes that's supposed to go to a little plug that is plugged in right near that fuse somebody will be along in a second and show you a picture of one and a good car My pictures are all too high resolution and have to be messed with to post them
Lot of dust in Mississippi the back roads and all dirt roads almost like the red clay of North Carolina
I had a Prius from rural Idaho I was working on for a while... Looked just like this. I couldn't stand it. I insisted on cleaning it up before I'd work on it. That was back when I convinced myself that I'd only work on clean Prius and the Universe was like, "Now I'm going to connect you with the dirtiest Prius I can find." YIkes!
Yeah same here I have to blow and spray mine down before I really start working on it just to get all the dust off so I can see the labels and stuff whatever
It goes to the DC-DC converter inside the engine compartment inverter assembly. It's exact purpose? Battery voltage sensing for the inverter? You really need to fix that.
Like TMR said its a sensing wire. Surprised its not throwing a check engine light on the dash with it disconnected. Here's a pic. 2 wires plug into that battery top mounted fuse assy one is the thick main 12 volt B+ cable that runs to the front jump point and has a 100 amp fuse the other wire is the one in question that has a 5 amp fuse as its just sampling the battery voltage.
When I undid mine by a mistake actually I hit it with something in the wire broke off the connector I had some light on until that was restored that I do know and I restored that connection immediately did not cap it off and leave it no sir