12V DC voltage drop for second switch 10 meters away
At 12V 1 Amp, at 10 meters (20 round trip), the voltage drop would only be 1V or ~9% with 22 AWG wire. With 18 AWG wire it's only .42V or 3.5%. This shouldn't be enough to cause an issue with the solenoid. If the solenoid is directly powered by the switch, and not with a controller.

If directly powered, you could resolve this with a second power supply and a relay. The relay would be connected to the original switch with a short connection to reduce issues. The relay will also be low powered. With a smaller load, the length of wires is not as much of an issue, so the voltage drop will be smaller. Any common 12V automotive relay that has a 2 amp rating on it's switched side and ~200 mA or 0.2A on the coil side would work.







simulate this circuit &ndash; Schematic created using CircuitLab