I have a after market alpine radio with an extra amplifier in the back for a subwoofer. It has beens there for years with no problem.

I am selling the car so I went to remove that amplifier to keep. I disconnected the wire from the positive terminal of the battery which powered the amp. Then I removed the amp and taped off the ends of all wires that has led to it. I inadvertently unplugged the wiring harness from the other amp that I think is original equipment so I plugged it back in.

With the key in accessory position the radio worked just fine so I thought I was all good.

I went to start the car. As they key passed acessory the dash lit up then suddenly, nothing. The whole electrical system went dark. No dash, key won't turn, no lights, nothing

Is there a master fuse or relay I can check before I have to tow it?

Thx