Are these things worth even having on a cummins.I dont care about a little smoke.Are they needed for the engine to run properly.Can these be taken out completely?
Hurdy, the Cummins 6BTAs have the same air heater circuits as the 6CTAs.
I removed the circuits on my 6BTAs before I installed them in the Blackfin.
The circuits can be problematic over the long term and have killed more than their fair share of alternaters. The amperage draw when the dam heater circuits are cycling are huge.
Also by removing the circuit you eliminate 50% of the onbaord engine's wiring harness.
Alternatives to the heaters are:
1. Do nothing, your engine will fire up just fine the the cold Bermuda temps.

2. If you have 120 volt current @ your dock install a 250 watt block heater 24/7 365. It will keep the engine coolant about 100F warm. Nice warm starts with minimal smoke.
3. Keep the air heater circuit, bypass the auto module and install a momentary switch or timer @ the dash. Many owners who subscribe to boatdiesel forum who "keep the air heaters" use this alternative.
I have 250w block heaters on my 370s.
If the power is off (beginning tomorrow @ my marina) the engines fire up cold no heat down to 25F. Just a bit more smokey.
No biggee.
FWIW,
Bill D