Top feed Injector Resistor wiring

[hks240sr20]

Hey I have a set of Low Impedance Top feed RC Injectors and I have purchased the dropping resistors that Jim Wolf Sell's to match the impedance properly. My question is that in the instructions it says to wire them on the V- wire to the injector. In the pin out diagram of the SR harness it has a Signal wire, and it has a ground wire, i've wired them into the signal wire but no where can i find is that is a positive voltage or negative voltage wire. So if anyone know's what wire the resistors should be wired into, please let me know. Thanks.