I have an Epiphone SG (G400), which had possibly the crappest sounding stock pickups I've ever heard. I had some old pickups from a 1970s Les Paul copy that I took out cause they weren't potted, so I potted these and went to install them in the SG. Here's the problem...

The stock pickups not only sucked, but the bridge pickup hasn't worked for several years - I assumed from when I was a kid and pulled a screw out of it, put it back in, and it hadn't worked since. Very low signal but it is present.. When I put the new pickups in, it's doing the same thing again?

I know that both the new pickups work as there were no problems (other than feedback) when they were in the original guitar, and it's not the switch as I reversed the wiring and it did the same thing but obviously reversed.. I also replaced the volume pot on the bridge pickup and that didn't do it either.

ANY IDEAS?! I love this guitar and would love to have it working, and these old pickups are pretty sweet too. Please help!
PRS SE Chris Robertson
PRS SE Angelus Custom
Yamaha SF1000 (Both of 'em)

Laney L20H Lionheart
Marshall 1936 w/ Eminence

Rather large pedalboard..