12v Socket power issues

[Seorsum]

Hey everyone, my 12v socket has had an issue since I used a 12v car heater. My heater core leaks so I bypassed it; I needed heat for defrost in the winter so I figured that'll help. It worked for a bit then it just stopped working mid-use. The socket still works and powers on the light for the heater and also phone chargers, but it never gives enough power to actually turn on the heater or charge any cell phone or iPod, no matter what charger I use.

The fuse is good and I'm just confused. Could it be the wiring?