Power from Taillight is wired to fuel sending unit... Check!

65 Diagrams from MyMopar:

http://www.mymopar.com/downloads/1965/65ValiantBarracudaA.jpg

http://www.mymopar.com/downloads/1965/65ValiantBarracudaB.jpg

See diagram "A" top left of page is the kick panel connector

1...Dark Blue is your sender

2..BLACK is tail

3..DK GREEN is turn

4..VIOLET is backup

5..No Connection

6.. BROWN is turn