I have an electric 12V engine coverlift mechanism (1) that is draining the battery when ever the hatch is opened. If engine is running plenty of juice no problem (just spikes the volt gage way down) . Is this normal? Can theses be rebuilt? If I need to replace it would I be better off with an electric one or hydraulic one plumbed into the trim tab pump. The boat is 89 Scarab, battery was just replaced. The hatch has the sunpad.

I would check your wiring first. I believe that most mechanical lifts are powered by wiring that runs from the battery all the way to the dash switch, and then back to the hatch lift. If the wiring is too long, or if the switch is not 100%, you will have a large voltage drop. Try running the lift once manually with short heavy jumpers directly to the battery. This will let you know if the lift is O.K. I have also seen where the sunpad is so waterlogged that is makes the hatch assembly too heavy for the lift.