[fortyonerag]

My only issue with using resistors to provide voltage drop is that the drop they provide is dependant on the current draw of the circuit (if the current varies, so will the voltage drop).

Solenoids are pretty steady, so to check that 1 Ohm resistance is enough, determine the current draw of the solenoid. Ohm's law (V = I X R) can then be used to work out the voltage drop across the resistor.

As an example, at 5A draw, a 1 Ohm resistor will account for a drop 5 V off the 12V leaving you with effective 7V at the solenoid.

A spinoff of Ohm's law is P = I X I X R meaning you will also be consuming 25W of power as heat in the resistor, so just remember it's going to get warm.