No power to sylinoid, what should I do?

If auto trans, check that the range switch is working, this is the switch that stops the car from starting in gear on an auto. Take it to a mechanic to have the starter, transmission, radio, anti-lock brakes, evaporative emissions, or auto-load-leveling system diagnosed. There's dozens of solenoids on the car and they all get voltage at different times to do different things. Most of them are run by some type of computer module. Those computers don't fail real often so first your mechanic has to determine if the computer is getting its voltage, usually from multiple sources, and if all the "inputs" are working. Inputs are sensor signals and on/off switches. If all of those are good, he has to check the "outputs" meaning things the computer controls, like lights, motors, relays, and solenoids. Once all those are eliminated as causing the problem, the last suspect may be the computer.