Upgrading MTH PS-1 SD45 to TMCC

Only you can decide if an upgrade makes sense for a specific locomotive.  I can tell you that wiring the lights can be done quite effectively with the Cruise Commander, though it takes a little work.

The smoke unit is simple, it's basically two wires as it will run continuously.  One of the wires will go to frame ground, the other to the smoke output of the Cruise Commander. 

You'll bend up stripping most of the wiring out of the locomotive to start, then putting in what you need.  You can use the PS/1 electrocouplers for the Cruise Commander, you just need to splice on the connectors to the board.

If the locomotive has lighting boards, you may be able to use them, I don't know the specifics of what you have. 

If you really want to go crazy, here's a light package I put into a BEEP using the new Cruise Commander Lite. This light package has directional red/green markers for direction, dual headlights, and a strobe.  This is all controlled by the two lighting outputs of the Cruise Commander, and all the lights will turn off if you kill the lights from the TMCC remote.

Note that the load resistors are no longer necessary, they were only there for the beta versions of the CC Lite, and not ever needed for the standard Cruise Commander.  Note that I used the smoke control for the number boards and strobe, but you can wire them direct to track power or drive them from the combined lighting outputs if desired.

Thanks! This diagram is super helpful for all the lighting in the SD45. 

I hadn't thought about the frame ground for the second smoke wire though that makes sense. 

A few more questions/assumptions:

I'm seeing what appears to be a optical tachometer mechanism on top of the second motor - do I simply ignore that since I'm ditching the PS-1 sounds? 

I'm assuming I can bypass the smoke switch and manual volume adjustment dial since all of that will be powered by the RailSounds and Cruise Commander boards? Guessing it might be best to just undo and cap those wires? Could I use the smoke on/off slider switch as my TMCC program/run switch? 

If it has a tach on it, it's either Locosound or PS/2.  How about a picture of the electronics in the locomotive?

Truthfully, when I do a conversion, I normally rip out most of the existing wiring.  Obviously, you can use the switches for the Program/Run and Smoke On/Off if they're present.  I remove all the old controls when I do the conversion as well.

Most of the time, I end up with the motors and the smoke unit bare, then I start wiring.  I typically want LED headlights in any case, and LED markers as well.  I frequently use incandescent bulbs for the number boards as they spread the light out better, and I run them on low voltage so they don't get hot.  Lighting usually gets hot-glued in, it's quick and easy.  If I have cab lights, I use incandescent bulbs for them as well most of the time for the same reason, spreads the light better.

If you want to get fancy, here's a little module I've hand-wired up a couple of times to control lighting, I've also used it to control smoke when I stop.  It senses motor operation and closes the relay.  This can be used for Rule-17 lighting, controlling the cab lighting to turn off when you're moving, and turning off the smoke when you stop.

For Rule-17 lighting, I use a set of contacts to bypass a series resistor to the LED lighting and only leave a small resistor for full intensity.  For cab lighting, it just turns it on when the engine stops.  Smoke can be turned off when you stop, if you're clever, you can do all three with the module.

You better post the catalog number for the locomotive because like John alluded to, PS-1 do not have tachs.  Also it might tell him if you can use the couplers or not with the ERR boards.

John, can you still use LEDs for the cab and number boards with your circuits here?

If it has a tach and electrocouplers, I'm guessing it's PS/2, and those electrocouplers are NOT compatible with the Cruise Commander.  Locosound locomotives have the tach for speed control, but do not support electrocouplers.

You could use LED's for the cab and number boards, but you would have to include current limiting resistors and the diode protection like the other stuff has.  If you use the smoke output, you also have to keep in mind it's polarity is opposite the lamp outputs.  Never did understand why they did that...

Sounds like it's a Locosound as the couplers are not electrocouplers. What I thought is a tach is a disc on top of the rear motor with black/white vertical stripes on the sides and what appears to be an optical sensor next to it to read those stripes. I'm assuming this is the sensor that causes the engine noise to adjust based on the speed of the locomotive. Maybe "tachomoter" isn't the correct technical term here. As you can tell, I'm new to this!

I'm going to order up the Cruise Commader and RailSounds boards as well as a pair of electrocouplers and give this a go. 

That's the motor speed tach.  If it doesn't have electrocouplers, it is probably Loco Sound, most of the PS/2 stuff has the couplers.  The key is, is there a battery connected to the package?  If so, it's PS/2, if not, it's Loco Sound.