Dead HV Battery

This latest car I bought has, lucky me, electrical problems. I hate electrical problems. Look at this pic the auction provided:

41895344-Image-8 hosted at ImgBB — ImgBB

If you zoom in, you can see the Battery light on the screen, the triangle, and the CEL. Also, all the other lights seem to be functioning as normal. I was hoping it just needed an HV battery, I have one of those.

Got it home, and it looks nothing like that. Nothing on the dash lights up except both turn signal lamps stay lit, which makes sense because all four turn signal lamps outside are lit; they just stay on, not flashing. I can also see that someone has been looking in the fuses boxes - both tops were off. And, my luck, the 100a main fuse in the under-hood junction block was blown. That's always a PITA to replace.

I checked the fuses. Under the hood, Dome, EFI and Throttle fuses were blown. All the inside fuses were good. When I replaced the blown fuses, the Dome and Throttle fuses blow again immediately.

Blah, blah, anyway. I'm trying to figure out where I'm trying to get to. I'm not sure where my problems end and a (potentially) dead HV battery being. IDK what the car would do if only the HV battery was completely dead vs what it's doing now.

The point being that I don't want to swap out the HV battery if that's not the problem. Since I have blown fuses, I expect there are other problems.

What's pretty obvious is that someone at the auction screwed with the car after the pictures were taken. It's highly likely that someone tried to jump it and had their cables crossed. I've done that a couple of times, but I never had other problems from doing so. I just replaced that main fuse and it was good again.

Am I correct in assuming that the 100a fuse was good when that pic was taken? What else might have happened to cause all that? What would be the effect of the HV battery being completely shot? Maybe that's what's mainly wrong.

 

How do I know whether the car has DRL or not? Maybe that's why the turn signal lamps stay on? IDK.

 

DRLs, from what I'm reading, were an option - maybe in just 02-03? I never knew of such and don't know how to know whether you have them except to look during the daytime.

Both arrows are on on the dash and the turn signal lamps are solid lit on each corner, although one is dimmer than the other. As always, I forget to check and this car is at the storage lot about 5m away, but I think those lights stay on as long as the 12v battery is good, and I think the headlights do too - they weren't before because of a burnt fuse. The steering wheel switch is turned off.

Occurs to me that it might be the AutoOn feature messed up - maybe the light sensor isn't sensing and makes the lights come on. Except in the back it's just the turn signals, not the taillights.

So, obviously, something is messed up. But I'm thinking it's higher up the wiring diagram, because nothing works now, and from the pic, everything did at the time it arrived in the auction. I'm thinking - which ain't good - that whatever made everything lose power, has messed with the headlights too.

The obvious answer was the ECU that's part of the speedo cluster. Its window was broken in the auction pics. But I had one and have swapped it in without anything changing.

I guess the next step is to swap an HV battery in just to eliminate that as a cause of things.