I refitted the loom to my 3dr a while back and im pretty sure i put the earth for the blower on to the part of the bulkhead that the bottom of the wiper motor bolts to, Im not sure if that's where it was originally as I didn't label it up before removing it as I didn't think it was important, I'm crap with electrics but I thought as long as it's earthed out somewhere it should be ok. My blower occasionally doesn't work but seems to be the plug slightly at fault as it will come on if I wiggle the plug about.