thinking of tapping directly into line 4 (r-y) from d4 for the varial ground to my puddle lamps. Does anyone see any problems with this?

would I need to do anything other than tap in, like a diode, maybe? also thinking it would be good to fuse, but I usually fuse right after tapping power, and wonder where the best location for a fuse would be in this case...one on each end?

I agree to indemnify you =)

 

My largest worry (assuming you don't reverse polarities) would be the added load on that single solid-state component.

I don't know how much load your 'puddle lamps' add and I don't know the designed capacity of the controller, but sooner or later if things keep getting added, one will exceed the other and a new $425 controller will be needed.

 

would capacity of the controller be documented in the service manuals?

( the puddle lamps are 10 LEDs connected in series)

 

It's not in the manuals I have, but the 'normal' load is under an amp, so I doubt that it's actually designed to handle much more than that...

Tom