Other halfs sisters car, driver side window seems to work intermittently. She'll open it perfectly well, then later can't close it... When I went to have a look it suddenly works fine again. Points to loose connection but can't see anything obvious. Anybody got any suggestions? Are there relays or a control box of some sort I can look at, know any common faults? Her passenger one died one but that was a knackered motor, this one just seems to only work when it feels like it.