Hey all,

Could someone please confirm that this cable is truly the lead to the original proportioning valve? If it's not, any suggestion what it might connect to? Thanks a lot. Mat

 

Thats it, to verify just turn on the key and ground the wire end, the brake light should come on with the Ebrake off.

 

That wire connects to the brake differential pressure switch that is built into the combination valve or distribution block (what people incorrectly call a "proportioning valve"). The purpose of the differential pressure switch is to illuminate the BRAKE light on the dash if you lose pressure in one half of the dual circuit brake system.