took the battery out to replace on my mercedes clk 320 convertable year 2000, now i can't get into my trunk a d the manual key won't work ...

not sure,you may fry some wires,sorry cant help you on this.maybe someone else will chime in.

It works as long as you don't do anything just open trunk you're good

Aply power in engine bay on driver side , pull up a square cap with x signed just at the front end of the fuse box or next to left shock absorber. That is a positive two wire side , put the negative at some metal body or engine. You will have per to light up your dzsh, to open the trunk and to move your key and shift.