Bought this engine used some time ago . It had front end droop and found it to be a broken Bissel. Got that repaired ....... looked like it might have hit the floor . Finally found out why the smoke fan never worked . The board at the boiler had wires that were disconnected. After a lot of delicate soldering on the wires to the board , I had the engine running well with everything working except the smoke fan.
Even after resetting the engine the thing would take off running erratically henever I dialed in smoke on the full DCS with the remote.
I finally opened the boiler again today . Using the VOM I found no continuity from the fan motor gray wire to the proper pin at the back of the boiler. The wire was also combined with the gray wire from the tach reader . After finally finding the place I had to solder I wasn't quite sure if I had not soldered the wire to one of the other pins. ( there are ten pins for the small board )
The smoke now works well though .