I wouldn't think it does anything, going to empty pins. Maybe it does something on the 500E upwards. Those models have an EQ bypass and a mids EQ switch.
Fender American Standard Jazz Bass, Vintage Tint and Satin Finish. Custom Warmoth 51 Pickguard (white/black/white). Aguilar DCB G3 Dual Ceramic Bar Magnet Pickups. Fender High Mass Vintage Bridge.