Astatic 575m6 help needed

[Dan7667]

picked up one from a friend @ CBTRICKS, and unfortunately received DOA...will key up the radio, but no amplification at all...wiring to a General Lee, and noticed that pin 4 shows continuity to BK (supposed to) but also SH,WH, & RED...maybe its not wired correctly?
Any help sure 'preciated
Dan
PS
Pin 1 SH & BL
Pin 2 WH
Pin 3 RED
Pin 4 read above

 

[WA1BXY]

1-Shield and Blue
2-White
3-Red
4-Black
try this i think this is the way it goes, but i am not sure :?