I bought a couple of nice switches and a 1044 transformer from a gentleman yesterday and I have a few concerns with the transfomer. The transformer works well with the throttle side however the whistle isn't working. It did work a couple of times with my engine (a mid 90's era Williams Santa Fe) but for the most part, it doesn't work. The concern is the amount of heat being generated on the whistle/reversing lever side. I took the lever off and the metal rheostat (I think that is what it is) is so hot, its practically untouchable. The throttle rheostat is warm like I expect it to be, not so hot that it makes me recoil from the heat.
I have yet to open this up. I'm very comfortable with opening the power pack and poking around in there with my multi-meter and seeing what can be fixed.
I'm assuming that its a pretty straightforward transformer inside the unit.