revbond,
If I read my 500E literature correctly the "base module" is in a black-lid metal box underhood. Look on the passenger side near the firewall...should have 4 allen bolts holding it closed. (note to Commerce GA Raceway tech inspectors...that box IS NOT the battery) Open the box, look for a module that has several fuses visible. If memory serves it is the "box" closest to the fender. You will have to ask Benzmac on the procedure for replacement of the fuses in that module. If you have to remove the module you will need a special tool.

Hope this helps...Lee