2023 Zforce 800 Trail G2
I'll start by saying, yes, I know I am an idiot!

I very stupidly tried to jump start it by connecting to the B+ terminal in the accessory block. After about 3 attempts, the dash went black and nothing works except the headlights!

Does anyone know where the wire goes and if there is a fuse somewhere? I am really hoping that I didn't blow the ECU. How could I check that? The starter also won't engage at all.

Basically, the only thing that works is the headlights, both the actual lights and the indicator on the dash.

Oh yeah!!! If I touch my finger to the main relay, I can feel and hear it click when I turn on the key.

[2015 Z Force 800 53/Trail EPS]

What we need is a wiring diagram for the 23 Z8 to see what's between that B+ terminal and the battery. One would think a factory acc block would be fused and maybe on a relay for safety. I don't think I have a wiring diagram but I will look. You have learn this but for others that have not, only jump a battery from battery.. or power source to battery. Starters pull something close to 20 amps and pulling that back through the harness and systems can toast things.

[2015 Z Force 800 53/Trail EPS]

Ok I found one and it has the wiring diagram. I will PM you a link.

Thank you so much! This should help a lot. I have a service manual for my Uforce, and it helped out a lot.

Sadly, I have scoured the wiring diagram 4 times, and the accessory block is not shown. I did find the pin on the dashboard for power, so maybe that will help a little.

[2015 Z Force 800 53/Trail EPS]

Sadly, I have scoured the wiring diagram 4 times, and the accessory block is not shown. I did find the pin on the dashboard for power, so maybe that will help a little.

That just means it didn't come with that acc. block. Just trace it out.

Final report!
It was the Signal A fuse!!! I tried chasing the wire, and I didn't get very far. I decided to try checking fuses again. I saw "Signal A" and "Signal B", and from the service manual, I knew they had something to do with power. So I checked the Signal A fuse, 15A, and it was blown. I replaced it, and everything came on as if nothing had ever happened! Many thanks to NMKawierider for the help and manual!

With the wiring diagram, I found that the battery goes to the Main fuse (aka Charge fuse on mine). The input to the Signal A fuse comes from the Charge fuse. The Signal A fuse feeds power to various things, one of which is the power pin on the dashboard!! So if your dashboard goes black, check the Signal A fuse first!!