Okay. Replaced the vacuum switch on the T-case, hooked her back up and the dash light still stays on.
Under the hood I traced the vac line to the blue plastic line going to the switch. When I unplug this from the blue line's diaphragm thing between the blue line and black vac hose, the light goes out and the engine RPMs kick up a bit. I still have 4wd hi and low with this line unplugged.
When I shift into 4 H or L with the line unplugged, the light acts as it should - comes on when engaged and goes out when disengaged.
With the line connected to the blue line, RPMs drop, 4 H and L still work fine, but the damn light won't go off.
Here's another thing. The last couple times I put it into 4wd during the snow, I noticed that the light woiuld stay on until I shut off the engine. Upon restart, the light would be off.
Since this started I've noticed a slight drop in MPG so thinking maybe the fork is stuck (?). Dunno.
Remember, the 4wd works fine except for that damn light. Could it be the diaphragm thingy?(someone please help me with a name for it).