Quick view Mechman P101 GM 4 pin plug pigtail with excite wire Now: $15.99 MSRP: Was: This is a simple pigtail that plugs into any oval shaped 4 pin GM alternator plug. The yellow wire gets connected to any ignition switched 12 volts. This is a great way to easily wire multiple GM alternators onto a vehicle, or ada… Add to Cart The item has been added Add To Compare