scanmaster problem?

[sixster]

as i posred in the ecm thread , i just got a t type
the scanmaster i have just says 2.1 when you start the car
& clicks off when you hit the brake , the light is very dim
but someone was nice enough to post instuctions in this forum - thank you
& saw the white wire is connected to
the f pin not e pin - i swapped them & it didn't work at all
does anyone know why the f pin would be used

thanks - rocco