Travis, the turn signal bulb is grounded via the hose clamp to the steering wheel column, it is not a failure of the turn signal flasher unit if it doesn't turn on, it may simply not be grounded.
There may or may not be a CB in the flame heater circuit. Wire #55 comes from the accessory switch. Go ahead and leave it out (for comparison, the flame heater on my 757 8x8 has a 15A CB in the circuit).
Some ground connections:
1) Battery (NEG) to frame ( via cable)
2) Engine to frame (via strap)
3) Dash to instrument panel (via 1/4 turn fasteners)
4) Front lamp fixtures to fender (via mounting screws)
5) Headlights to frame (via wire)
6) Fuel in-tank pump and level sending unit to frame (via wire #79 )
7) Engine mounted items to engine (via treads or dedicated wire (flame heater return))
Horn to steering column (via horn button)
9) Turn signal pilot light to steering column (via hose clamp)