Me and a friend of mine are putting a 5.3engine and a 6L80E trans from a 2012 GMC Sierra into a 1969 Chevy full size truck. We are trying to figure out all the details. We are using a E38 ecm. On connector J1, pin 9 (brake switch signal), does it require a positive or negative signal? Any help is appreciated.

 

Here are a couple if pictures of the progress.

 

Anybody?