Replacement lighting control module for motorcycles using the WIRE PLUS lighting control with 2 bundles. The rear bundle, (4 wires), is approximately 4 feet long. If your turn signals are no longer working correctly, this may be the fix you need. The 11921 lighting control was included on the new  style seat post mount, motor mount, mid frame mount except for WP181, and the flat side mount WIRE PLUS wiring systems. The 11921 lighting control module controlled the operation of the front and rear turns signals, provided load equalization and auto cancelling.  It also operated the rear turn signals as brake lights.

The 11921 has an additional white/blue wire that the 11604 does not have, so that if you do not want the module to generate running lights through the turn signals you may leave this wire unhooked.