The latest issue with my TC33D: the engine block heater now trips the GFI outlet in my garage any time I plug it in. I have not yet even looked to see where this is on the engine. I'm hoping it's not a big deal to get to. As far as I know, this was a factory installed item (could have been a dealer installed accessory, but I think they get all of the tractors they order this way).
Time to start poking through the parts and service manuals to see what I can find. If anyone has messed with one of these and has any good tips on what to look for, please pass them along.