The first thing is to check your vacuum at the relay.  Use a good vacuum gauge.  Pull the top hose from the relay and check that vacuum.  You should be seeing 15 - 20 inches of mercury.  Plug it in and then check the operating hose.  You should get the same reading.  Unplug the hose at the actuator and check the vacuum at that point.  With the lights off you should heve 15 - 20 inches of mercury.  If you don't have any vacuum, the relay is faulty.  The diaphram in the relay is sucked up and keeps the piston pulled up in the relay, allowing vacuum to be applied to the back of the actuator.  When you turn on the lights or use the headlight override, you remove vacuum from the top of the relay.  The piston falls and then vacuum is supplied to the front of the actuator which then raises the lights.  Once in the locked position, you should not be able to manually push them down.  You have to reach under the grille and push up at the pivot point of the front and rear link.   If you can push them down, the actuator piston is out of adjustment.