Connect the vss(spd) ecu wire to the speed 1 position on the gps. Then set unit to 4 in the pulse set up in the speed settings and thats it. Extremely accurate speed and I really just like having the outside air temp and compass heading on the speedometer.
I installed the vss from the gps to the ecu the way the tech guys at DD suggested and it works well. I am still not convinced the vss is needed but the more data the ecu has the better.
I recently installed a Dakota Digital cluster in my 73 with the add on GPS module. A couple years ago I converted my rig to 3FE and with that conversion I deleted the VSS function. I am happy to see the Dakota Digital module has vss to ecm output and I really would like to connect it to my ecm...