The Missing MARS Light

I have the simple answer:

The manufacturing homeland is working on getting their workers to the moon first....then China can focus on Mars.....

Sorry, I just could not help myself.

Likely it was a last minute decision. I know that Williams engines have a simulated MARS light and even that is pretty neat so I would agree that it should be there.

You would think so Jeff - with the Southern Pacific produced at the same time there would be less confusion to have them the same!

FWIW, there is a pretty inexpensive way to solve this issue, the Ngineering MARS Light Simulator.  I've put these in a few locomotives and I always keep a couple in stock.  They are one of the best simulators I've found using a single bulb.  To do better, you need multiple LED's.

I noticed the 2010 catalog discrepancy too and that put me off buying the Santa Fe version. I have the SP Alcos and although they are very nicely detailed, the Mars light function is inferior compared to (a) the TMCC version on, for example, earlier Lionel SF F3 engines and (b) the Legacy version on, for example, the Texas Special E7. Go figure.

I have used the Ngineering boards GRJ mentions in a variety of engines and they work fine. A little fiddly to install because the boards are so small but if I learned how to solder them together anyone can.

Why the difference between SP and SF? On that I can only guess because the Mars light function in Legacy appears to be controlled by the main RS board and there shouldn't be any difference between different RRs that had Alco PAs - unless someone more informed and purist tells me different. 

This might be irrelevant but I'm posting it anyway because I'm interested in the variations in Mars light treatments even just across Lionel engines and someone better informed might explain why the differences and how they work.

I looked at both the SP and ATSF Alco parts diagrams and they have rather different front lighting PCB boards although in both cases they don't resemble what I have found in other Legacy engines, such as the E7 and FEF3 both of which have Mars lights. Certainly in the FEF3 this light function is powered and controlled controlled from the main board.

The one for the SP version looks similar to the PCBs I have found in my TMCC F3s, which have a great Mars light feature:

This is the one for the ATSF, which also has separate PCB boards for the distinctive side number boards:

Looks to me like the difference in features was deliberate - although I am not sure why. 

One last thought; is there a Mars light icon on the Cab2 when running the ATSF? I guess there should not be.