On DADS50 post above, the photo (this thing) you notice it is two pieces. On mine, I had to run some folded sandpaper between the two pieces. Then it worked fine. It was not making connection due to a light coat of rust.
57 GMC LCF 370 55 John Deere 40-W 59 John Deere 430-W 2000 GMC 4x4 56 John Deere 420-W Pix on Photobucket