Just a couple of thoughts here as I have been following this.
Could the issue be poor continuity in the on/off switch to the voltage reg board? Could it be limiting the current available to generate the correct amount of heat? I would try to jumper the smoke on/off switch to eliminate this as a possible cause.
Also, wasn't there a change in where the on/off switch was placed in the circuit over the years? I seem to recall the smoke on/off switch used to be in the brown/black + wire going to the smoke unit. In latter engines, the switch was installed in the red + power feed to the voltage regulator. Should not make a difference, unless the smoke switch is off and the voltage regulator was being used for some other power needs.
I'm still racking my brain as to why there is full smoke when boosting power to the smoke unit and then it returns very little smoke when you stop pressing the smoke boost button. Isn't there a setting for high, medium or low smoke output? I would have to confirm this setting gets reset with an engine reset as I have never tested. Does it matter if you use a Legacy or Cab-1 to make the smoke level changes? I have had times when I had to use one controller vs the other to get things back to "normal".
I would also agree that the smoke unit needs to be tuned. I have had issues with the batting obstructing the air flow too much, causing poor smoke output.
John, If I am correct, the voltage regulator board accepts the boost smoke signal and then puts out more volts to the smoke unit. Could you confirm this? The other possibility is the voltage reg board is controlling/limiting the current. Again, I have never tested this to confirm. I have never had a voltage reg board fail like this. It was either all or nothing.
Dave
