Here's a design which should do what you need. A relay powered for the lengthy times you envisage would be a considerable current drain, so has been replaced by a MOSFET H-bridge. Standby current (i.e. actuator stationary) for the circuit is ~1mA. The GPS signal controls Q1. When GPS = 3V Q1 turns on, which turns off Q2. When GPS = 0V Q1 turns off, which turns on Q2. The voltages at Q1 and Q2 collectors control the H-bridge MOSFETs, rather like a see-saw, to reverse the current flow through the actuator motor. It is assumed that the limit switches 1 and 2 are normally closed. C1, C2 and C3 provide supply decoupling to damp spurious signals. The transistor types are suggestions only: many possible alternatives exist.