Just took another look at the print... I'm more awake now, so maybe I can explain it better......
If anyone's looking at the OEM manuals, I'm referencing P 71-2 and p 89-1 and 89-2.
Power for the interior lights is fed from a common circuit off the Battery Saver Relay. The BSR feeds the common splice, which feeds the dome lights, map lights, vanity lights, and glove compartment light (and the Electric Shift Control Module, and the power windows). If those all work, then we can rule out the BSR and the fuse that feeds them all.
The power for the interior lights passes through the afore-mentioned splice, then through the dimmer module via pins 1 and 2 through the connector on the dimmer module (C219). From there, it goes through the trigger coil on the interior lamp relay, which the GEM grounds to close. So, to turn the inside lights on, the GEM must ground that signal wire, closing the interior lights relay.
Now, that power fed through the power terminals on the interior lamp relay is fed from that same splice. It passes through the relay (when it's closed, of course), then back up to terminal 3 on the back of the dimmer module. The actual feed for the interior lights does not pass through the dimmer again... it shares the connection going back into the dimmer module, but does not pass through it.
Now, the power for the puddle lamps comes into the dimmer module at terminal 3 with the power for the interior lamps, and goes out through terminal 4 as long as the dimmer is somewhere between the on and off positions (all the way up or all the way down past the click). When you roll the knob all the way up to manually turn on the interior lights, it opens the connection from the power feed to the mirror lights, so manually turning on the dome lights leaves the puddle lamps off, but if the system turns on the puddle lamps (i.e. opening the door, or hitting the buttons) they do come on. The manual ON position also bypasses the interior light relay as well, so even if the GEM is having a hissy fit, you can still manually turn on the interior lights.
Now that that's out of the way, and I clearly understand it, let's check a couple more things...
If you manually turn the dimmer knob all the way up past the click, does it turn the dome lights on? If put the knob in the middle, the dome lights now work properly with the door pad and key fob, and door open, correct? But the puddle lamps do not work at all, correct?
If, I've read everything correctly from this post, your interior lights are working, the puddle lamps never come on. Check for power at the puddle lamp socket using a multimeter or test light grounded to a solid chassis ground, and if you still have no power there with a door open, you need a new dimmer switch (or you need to at least tear the dash apart and see if maybe one of the pins has worked its way loose from teh connector (not unheard of).
If you have interior lights, the only thing between them and the puddle lamps is the dimmer module and its connector (pins 3 and 4).
-Joe