@DanS - what bulbs did/do you run?
The Slee harness, it's a couple of relays and a plug that mates to one of the factory headlight connectors to switch it? Is this a common problem with it or did you draw the short straw with a unicorn?
Is the one that burns up the triggering connector or one of the headlight connectors?
Are there no fuses or fusible links?
Since it's the same connector you may have a bad ground for that side, which might still be there, lurking, waiting for an inconvenient moment.