Yeah a glowing rheostat is not considered good! The instument lamp circuit power:
- feeds from the B2 connection to the switch (that comes from the fuse panel for brake and parking lights)
- passes through the rheostat in the switch on the switch's I terminal
- goes back to the fuse panel on the tan wire
- feeds back out of that 'Instrument' fuse on orange wires to the various instrument lamps.
That 2nd fuse ought to blow if there is so much current through the rheostat that is glows. So there may be 2 things going on:
1) There is a short to ground on the tan wire somewhere
2) Somehow there is a short to 12v on the tan wire (or someone hooked a power wire to where the tan wire should go in the switch's connector) and it feeding power back through the rehostat into other circuits, like the taillights and parking lights
BTW, there may be 2 black wires or 3. This switch was used for years in many Mopars, and some models had the tailights and parking lights both connected to one tab (either the P or R conenctions) or separately to the P and R terminals. Your car appears to use just one connection for both parking and tailights, and appears to have both a black wire (tailights) and a yellow wire (parking lights) going to one of these 2 terminals.
Sure sounds like you are going to need a new connector body for this to work well. (You probably know that you can put a small screwdriver into each slot in the connector body and press a small tab on each terminal and release it from the body.)
