MacBook sleeps after seconds, no backlight when sleep sensor installed

After a small spill, when powering on, backlight comes on, chimes, backlight goes off, MacBook goes to sleep after a few seconds - it can be woken up and when shining a light on it, everything is there and works, but the computer continuously goes to sleep every few seconds. The battery is not detected by the MacBook and doesn't charge. After reading that this is a common occurrence after a spill, I decided to replace the sleep sensor/battery connector.

With the new sleep sensor/battery connector (purchased from ifixit), the problem persists. I decided to remove the sleep sensor/battery connector and reassemble the MacBook without one. Now it works perfectly fine when plugged in. Of course, this is better than my previous predicament but very inconvenient.

How can I get the sleep sensor/battery connector to work properly? The old one has some corrosion on it, which I'm assuming from is from the spill. I assume the new part works properly, but I don't have a way to test it.

The spill was localized to the trackpad/wrist area.

The last three digits of my serial number are -WGL.