Post War whistle inserted in a Lionel 783 Hudson problem

Actually I don't find that surprising. PW whistles seem to have their own personalities. Each likes a little bit of TLC.

Thanks.  I'm just not sure where to add the TLC!

Have you tried the whistle on both outside throttles?  Also, when was the last time the motor and relay were cleaned and tuned up? All of that can make a huge difference.

Roger

First you should check the transformer dc offset voltage, it should be staggered during the throw just over 1.5v then .5v at full whistle lever throw. If it's not, then it's time to clean the switch contacts or maybe it needs a rectifier disk/diode.

Tweaking the relay  contacts and their stops that are on the cars relay is what you can do to regulate relay performance. Ie make the plate sit closer to the coil. I even lube mine.

  If the issue is the whistle motor, when was the last time it was oiled or had its brushes/armature serviced?  Oiled top and bottom of the shaft?