I ran a four conductor under my toad and connected to existing toads light system with the use of diodes. I used cable ties to support it along the toad's brake lines. Use a five foot cord between a connector on front of toad to MH. It is a flat four connector on both ends.
Here is some information.
Wiring infoYou would need identify your MH as to whether it has amber turn signals or utilizes red brake and turn signals.
Same for the pickup. Verify whether it has amber turn signals or combined brake and turn signals.