Lionel Legacy K4 11319 smoke unit issue

I'd measure the power consumption of the the smoke unit fan motor using an external 5V power supply.  If it's more than 50ma, the motor is either bad or the impeller is dragging on the fan chamber.  If none of those issues are the problem, it may be the RCMC fan transistor, it's a ZXTN25100DZTA if you want to try replacing it.

I was going to post a similar question on a error code I am getting from a very early version Legacy Pacific (I was told it was a prototype).  In this case the manual I have says one blink is an error from the self check of the main smoke unit.   It is blinking the cab once.  I had been blinking three times (motor issue according to my manual) initially but I took the boiler off and made sure nothing was binding and that cleared.  Do the codes vary by model or maybe I printed the wrong user manual?

I have checked both smoke units (main and whistle) and while neither is working when I run the engine around (as it blinks) I dont see any obvious problems.  Would you all recommend disconnecting/desoldering the smoke unit and testing it?  If so is there a procedure/schematic or diagram showing what wire is the "activation" of the smoke unit?  I am not at all experienced with this and was considering just ordering another smoke unit and replacing that whole unit.

Thoughts?

Thanks!

@Robbin posted:

I was going to post a similar question on a error code I am getting from a very early version Legacy Pacific (I was told it was a prototype).  In this case the manual I have says one blink is an error from the self check of the main smoke unit.   It is blinking the cab once.  I had been blinking three times (motor issue according to my manual) initially but I took the boiler off and made sure nothing was binding and that cleared.  Do the codes vary by model or maybe I printed the wrong user manual?

A single blink is the drive motor, not the smoke unit, at least in all the manuals I have.  FWIW, the early Legacy before 2010 didn't use the RCMC electronics and there were no blink codes.  I'd love to see the page from your manual that defines the blink codes because that doesn't sound right.

This is the page from the Vision Line Hudson, one of the first locomotives to use the RCMC electronics, and AFAIK, the blink codes haven't changed for any of the later Legacy models.  I also believe that they erroneously left off the whistle smoke error codes as this model does have two smoke units.

Thanks John yep, whoops, two blinks from my Pacific.  It has two smoke units.  Bought it used (as well) and trying to get it figured out.

Two blinks, that would be the main smoke element.  That model doesn't have the thermistor, so I'd be checking the smoke resistor and associated wiring.  Hopefully, no wires pinched to ground that might have taken out the smoke FET on the RCMC.

Thank you John.  Have to take the auto train to FL tomorrow so will not be able to work on this for about a week but I will check those parts.

Out of curiosity do you (or anyone) know what built in test the engine runs when it powers up to detect a problem?  Is it current based (testing if the right amount of current is being drawn) and does it test the blower/fan as well?