Speedo:
Red - +12v
Black - Gnd
Green - Tranny Sending unit in.
Yellow - Light switch
Blue - Key on pwr.
Orange - Alarm output. (optional, I never use)
White - Choice switch. (other leg of choice switch is gnd)
4 in 1 gauge:
Green -
Oil
Blue - Fuel
White - Temp
Red - +12v
Yellow - Light switch
Black - Gnd
I just happened to have a set in the box out in the shop for a Jeep I'm building.