The battery in my 1983 500 SEL euro has gone dead once a year for the past three years. The local garage always replaces it with a new one (at no cost) and it lasts all summer until I put the car away for the winter. This year the new battery went dead after the car sat at the autobody shop for three weeks. I checked with a Mercedes mechanic who suggested checking the pump for the power door locks. Sure enough with the ignition off, the circuit was still drawing current. I pulled the fuse and the draw stopped. Where is the pump located? Can I disconnect it and still use the fuse for the clock and the four way flashers? What is involved in changing the pump?

Thanks for the help.