Blue now goes to L. Blue is not the "8th" wire, it is one of the 7 wires on a standard signal stat 900. Pilot. The L terminal flashes the left or right lights on the truck and the blue is just attached to it so an indicator light on the dash or on Signal stat also flashes. On a three prong incandescent lighting flasher, L and P are the same thing.
Never heard of a 900 with 8 wires coming out of it. I'm with Jorb, can we see the info you have?
Other
post.
