I'll tell ya what you won't be missing...!
That connector gives power only when the ignition is on, so you're just tying into the relay that runs that wire, if it even has a relay...simply turned on by the turning of the ignition switch to complete the circuit. Either way it works.
90 MX5 281k miles! - euro spec, Porsche Riviera Blue w/black hardtop, 97 motor swap, vintage Borbet rims, GC, FM shock hats/frame rails/rear sub-brace, AGX, sway bar, stb, Fidanza/ACT combo, EBC Yellows
92 COMMA SM - new paint coming soon...
'94 Black & Black & Tan
'99 head swap, JR header, TDR intake & header blanket, MegaSquirt, RB hollow bar, Tein Flex, 15x8 6ULs, HD M2 Sport, FM cat, Borla cat-back, black '95M interior, MOMO Zebrano, IL Motorsport console...
Dyno Days
8/16/08 (bone stock): 103.1 hp/99.0 lb-ft - Dynojet
8/23/08 (Borla cat-back): 108.2 hp/104.1 lb-ft - Dynojet
8/13/11 (more stuff...): 126 hp/116 lb-ft - Mustang dyno
Roger Moore: the Danny White of James Bonds