When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I don't see how it could integrate with the brake lights using only 4 wires. It also appears yours is missing a separate lever that gives 4-way emergency flashers. A google search on Model 730 / 6 pulls up a lot of threads on other forums about this unit.
4 wire does not incorporate the brake circuit. You will need separate/additional lamps in the rear to operate the turn signals independent from the brake lamps.