Smoky heater is likely caused by having old leaves down in the cowl vent.
Ok, it looks like there are 4 sets of circuits that go through the multi-function switch. Disconnect both cables, and test the following:
Set the turn signal switch to center, with the hazard switch off, and there should be continuity between 551 (lt grn) and 9 (lt grn/org). There should also be continuity between 551 LG and 5 (org/lt blu).
Set the turn signal switch left, and there should be a closed circuit between 44 LB and 9 LG/O, and 44 LB and 3 LG/W.
Set the turn signal switch right, and there should be continuity between 44 LB and 5 O/LB, and 44 LB and 2 W/LB.
Turn on the hazard switch, with the turn signal switch in the center, and there should be continuity between 385 W/R and 551 LG, 385 W/R and 2W/LB, and 385 W/R and 3 LG/W.
Finally, flip the headlight dimmer. There should be continuity between 15 R/Y and 12 LG/BK when it's in High position, and 15 R/Y and 13 R/BK when it's in Low position, and should flip back and forth between the two states.
If it fails any of those 11 checks, then you need to replace the switch. If it passes all of them, then we need to start looking elsewhere.
Also, check the High beam indicator lamp. It may have burned out.
Spott