12" heatbed relay issues

[pichuete]

its that melted plastic in the "out" output? . something that i have notice is that this terminals needs to be tight very well because the tends to loose . if you hear a click your relay is working but maybe you no longer have contact in that output . you can find those type of terminal in a local electronic supply store . also i suggest that you put the negative wire passing thru the relay instead of the positive .

worst case you can solder the wire directly on the back of the plate on that output (be careful no to short it)

also looking at the pic i think you have your heater 0 (extruder heater) inverted