If you only need to drop voltages over 12 a zener diode and a resistor would work fine. Wait till you get your data sheet before you do anything as there may be current limit resistors built into it which would allow for 14 volts. LED's don't work nativly on 14 volts so it's likley a series/parallel array of LED's, these really should come with current resistors built in, but no guarantee's. Even if it allows for the highest static voltage you'll want to use something to prevent spikes which can occur during solenoid switching which can be WAY above 14 volts (100+) for brief periods. Even for brief periods this will fry an LED.