Wired like the last diagram. Bilge works but still no LED. Even tried 3 different switches just in case LED may be bad. I also tried reversing polarity to no avail. Am beginning to think both "F" posts may need to be connected. They do meter out when using the ohm meter, wether switch is on or off, so am guessing 2nd post could be for continuation purposes.

Google search for wiring a 4 post comes up blank. I might just give the seller a call to see if he knows.