Adding Cruise Commander M to Lionel Standard Gauge Hiawatha

I think I figured out the serial data connection location- using prior posts which showed the antenna connection (pin 23) is right by the serial data (pin 24)- I used a continuity tester and confirmed my suspected serial data location is correct

You will MOST CERTAINLY want to do a couple of custom things to this installation.

• Remove the large bridge rectifier and tether it to the board.  The rectifier is bolted down to the chassis firmly to dissipate heat, it's a very critical step for something that large with two large motors.
• Make sure you have sufficient heatsink for the motor driver FET's and they also need a good solid mechanical connection to a large mass of metal for proper heatsinking.

Thanks- you are referring to the bridge rectifier in the middle of the new board right? So you remove that from the circuit board and mount it on the frame as a large heatsink?

Then for the other 4 FET (those are the ones that the screws go into right)- maybe add some extra heatsinks on the outside of the mount where they are screwed in?

You wouldn't happen to have any pics of a similar job?

found this post:

https://ogrforum.com/topic/how...or-4-motor-operation

Yep, some people have gotten away with minimal to no precautions.  OTOH, since I see a ton of stuff coming through for repair, I've probably seen a larger quantity of failures.  Pretty much all the stuff coming to me has had some sort of failure or it wouldn't need repairs.   I've replaced ton of triacs and FET's over the years, so I prefer to do the job once and not have to revisit it.  You can shoot the dice with no heatsinking, but you may be paying for it later.