I was trying to install an in-tank walbro 450 into my civic. I wired in a relay and pretty sure everything was all good, but when I hooked the battery up, it started to smoke instantly and I melted some grounds. Now I’m trying to fix that. I melted the ground going from the Fuel pump hanger to the front of the car, along with the Fuel gauge sender ground. I removed the aftermarket relay and wired the stock fuel pump wire back to the pump. I ran a new ground from the pump to one of the bolts for the seat belts. I sanded the paint off to make sure there was a good connection. But when I turn the key to prime the pump, it doesn’t prime. I checked the fuel pump fuse under the dash with a multimeter and there’s still continuity. what could be the problem? What else Can I check? The fuel gauge sender is still unplugged. Would that keep it from priming? I’ve been stuck on this for a few weeks now...

Also, I have a fuel pump kill switch and before I messed everything up, when the switch was on, I would have a check engine light, and when it was off it would go away. Now the check engine light is always OFF whether the switch was on or off.
thanks.

Help plz. I checked the ecu fuse and it was good