Helpp pleasee

So I just installed new pickups onto my Squier Telecaster. (MIA Fender Telecaster Pickups)Anyways when I select either my bridge or neck pickup it sounds fine, when i select both pickups(middle position on selector) it becomes mega quiet and crap sounding. Does anyone have a clue what could have caused this?

maybe the pickup is too low?

i dont think so, cause both of the pickups sound fine on their own, but when i want to use both of them at the same time it loses quality

Check the wire that's activated when it's in that position? You DID just replace the thing so you might have knocked something out of place.

Definitely check the switch, you may have not soldered something or you may have a bad connection. Hard to tell without looking at it though.

i didn't solder anything, i cut the wire close to the pickup, and just spliced the old wire to the new pickup, put some heat shrink over it