The resistor needs to be in
parallel with the lamp. You may have chosen the wrong wire on the lamp so that the resistor is not really in the circuit (both sides of resistor connected to ground). Make sure your ground is really a ground. A
VOM will help troubleshooting efforts. See the FSM (link in my sig) for wiring diagrams, wire colors, connector pinouts, &c.
Edit: And make sure you have good connections at the resistor and where you tap into the system. A VOM will be a big help. You can find cheap ones that are adequate for this job for $5-25 dollars at most auto parts stores or just about any store with an electrical department (eg, Ace Hardware, WalMart).