posted 07-22-2003 10:32 AM ET (US)
baltica,What you propose is, in fact, an idea that Whaler used for the bilge pump option on the 16' 7" models back in the 1960's. You can see this option in all the old Whaler catalogs. It is an amazing simple idea.
Just install a connector that matches up to your stern light plug. Whaler typically used the oft annoying black two pole connectors that are universally available, but you are free to use whatever connector you like so long as both the stern light and the bilge pump use the same fitting.
Both the light and the bilge pump will use the "anchor light" portion of the lighting circuit. When you want to use the other, you just unplug one, and plug in the other.
Probably best to limit the size of the bilge pump to a small Ruler brand 500 gph or less pump (or equivalent).