fuel guage reading full all the time

[NICKVW]

I just swaped a scirocco engine into my caddy and using the caddy's fuel sending unit, which has two wires purple and tan. but the scirocco's fuel sending unit has three. Red/yellow: tan: and tan/black. does anyone know how to wire the three into two, do i not use the tan/black wire?

OR, could it be a resistor behind the instrument cluster?

thanks

[caddyshack]

look up Funk Soul Kitty's website and leave her an email on there, what she doesnt know about Roccos just aint worth knowing!