Anyone have experience with Option M605 (headlight aim control)?

[Cloggie]

Hello all (and particular the European contingent). Just bought the parts (used) for the M605 option which adjusts the headlamps vertically. I have problems getting the lights set up the way that I want for night driving, when I set them for just me in the car, then they tend to be too low when fully loaded (wife, luggage etc). I have good strong headlights (H4 100 watt bulbs) and am thinking to converting to HID - which will exacerbate the problem.

The system seems to be quite simple, being vacuum actuated, but I can't find any workshop information about it. I really have only two questions. One is where does the system tap into vacuum? Does it go all the way back to the engine compartment or does it tap into the power brake booster or other source?

Second thing is what is needed to connect the actuator to the headlight. I have the stock H4's, just wondering what is different between the two - I would hate to replace my nice headlamps so I am hoping the connection is simple one.

Anyone know?

D.