I was thinking that that fan relay had 5 pins, because I searched Rockauto.com and it says that
1995 CHEVROLET LUMINA APV 3.8L 231cid V6 MFI (L) : Electrical-Switch & Relay : Fan Relay ACDELCO Part # 158719 More Info {5 PIN, MINI, BLACK #12193601}
RELAY,FAN CONT CODE 3601
And regarding the a bad plug, I have disconnected the fan plug, and run my own wires to the fan, but the fan did not run. The voltage during this was lowered though to about 10v, and I just assumed it was due to a poor connection I have made with the wires.