Skip to main content

Lighting for Your HO Scale Model Locomotive

  • Author:
  • Updated date:

Proper locomotive lighting can bring realism to your HO layout!

I purchased the Life-Like Trans-American Express Electric Train Set from Amazon. It was a cute starter set with pretty good detail, the one thing I did notice was the poor lighting setup in the locomotive. It had a single incandescent light bulb and used plastic light guides to channel the light to the headlights on the locomotive. The lights on the locomotive would change intensity with the speed of the train which was truly un-life-like. The picture shows the single incandesent bulb in the locomotive.

What is a "Mars" light?

Another thing that was missing from the Sante Fe model train locomotive included with the set was a Mars light on the front of the locomotive. A Mars light was a special warning light used on locomotives beginning in the 1940s. The light beam would oscillate typically in a figure eight pattern in order to catch the eye of motorists and pedestrians.

Take action! Add realism to your HO Scale locomotive!

Well, I guess I can't expect all this lighting detail from a starter set, but then it made me wonder how I could:

1. Maintain the same light intensity no matter what speed the locomotive was going, note my started set is a standard DC system, this may not be a problem with DCC (Digital Command Control) systems.

2. Simulate a Mars light on the front of the locomotive.


Build a constant light intensity circuit for your HO Loco

Here is the constant intensity light circuit I used, I broke my first rule of "breadboard first" as I have built this circuit many times before and it has always worked like a charm. This circuit connects in series with the DC motor in the loco and provides a constant voltage to a LED to be used as a headlight on the locomotive. Here is a picture of the completed perf board.


Build a Mars light circuit for your HO Scale Locomotive

Below is the circuit I used for my Mars light. This circuit was intended for a rotating beacon on a lighthouse but it worked equally well for a Mars light. I substituted the incandescent light bulb for a high intensity LED. Now I did breadboard the beacon circuit first because I have never used this circuit before and needed to know that it worked to my liking before committing it to perf board. Here is picture of me testing the Mars light circuit to be used for my Mars light on the front of the locomotive. Note: The circuit does not make the LED perform like a real Mars light; it just makes the LED vary in intensity as it is turning on and off like an incandescent light would.


Committing the Mars light circuit to perf board

Once I confirmed the Mars light circuit functioned to my liking I committed it to perf board. Notice how tightly I spaced the components together so that it would fit the body of my Sante Fe HO Scale locomotive.


Alert, space problem in the body of the my HO Scale locomotive!

I had to remove some of the steel plates used for weight in the locomotive in order to make room for the constant intensity and Mars light perf boards. I carefully weighed the locomotive on a letter scale including the upper body shell before removing the steel plates.


Mounting the circuit boards in the locomotive

Here is picture of the both the constant intensity lighting perf board and the Mars light perf board mounted in the locomotive. The top light on front of the locomotive is the Mars light, it flashes on and off about once a second, the bottom light stays on at a constant intensity. As soon as the throttle on the power pack energizes the track to a couple volts both the constant intensity and Mars light circuit starts working. Note: Unlike incandescent bulbs, LEDs only light when the properly polarity of voltage is applied to them. As such the constant intensity and the Mars light are only on when the locomotive is traveling forward. The sharpie marker in the picture is keeping the drive wheels on the locomotive above the track while letting the wheels used to pickup power on the track, this allows me to test the locomotive while in place.


Adding weight back to my Ho Scale locomotive

And now I need to add weight back to the locomotive to compensate for the steel plates I removed so that my constant intensity and Mars light perf boards would fit.

Scroll to Continue

Final Assembly

Here is a picture of the properly situated lead weights. I used stick-on weights from Amazon. These weights are typically used in the automotive industry to balance tires. Caution: These weights are made of lead, you should wash your hands after handling them and do not allow children to handle these weights. If children are going to play with the locomotive then I recommend using some other means of adding weight. Try to get the weights as close to being over the wheels as possible.


Front view of the loco

Here is the front of the locomotive; I had to slightly enlarge the headlight mounting holes to accommodate the 5mm High Intensity LEDs.

Watch a videos of my Ho Scale Locomotive with updated lighting!

Vintage Tyco Ho Scale stuff on eBay

I grew up with Tyco model railroad products when I was young. These products make me remember a simpler happier time.


Conclusion: So with some knowledge of electronics and little hard work and you to can have authentic looking lighting on your HO Scale locomotive.


nearboston on December 30, 2013:

Dumb Question. The schematic shows one bridge and no resistors, the perf board has 3 and 2 resistors. Why is that>

norma-holt on May 22, 2013:

Nice lens and the instructions are great. Model trains still fascinate me and they are a favorite with my grandchildren as well. Why doesn't your video follow the train around the track?

mouse1996 lm on August 16, 2012:

This is very cool. I always wanted to play with my brother's trains as a child but he wouldn't let me. I might have to get a train set of my own now. :-)

RinchenChodron on July 22, 2012:

Great job using the camo background.

Miha Gasper from Ljubljana, Slovenia, EU on July 18, 2012:

This looks like a great Saturday afternoon project:-)

AJ from Australia on April 26, 2012:

You make this look so straightforward that I think I could even do this. Blessings.

BlogsWriter on April 07, 2012:

Trains can be addictive, I remembered my craze for the toy trains when I was a kid.

Edutopia on January 31, 2012:

Great lens, even though this can be rather technical for some it never appears too inaccessible for even the layman to take a swing at. Good job!

MaartjeJepsen on December 20, 2011:

Great tips! Reminded me that my son loved playing with trains long time ago. So cute!

jbdkz (author) from Cleveland on December 16, 2011:

@Violin-Student: Glad you liked the Lens Art! I have an O and an N scale layout as well, but do most of my experimenting on the HO scale layout.You should check out my other model RR Lenses...............

Violin-Student on December 15, 2011:

This is fabulous! Thanks for the info. I run O-27, but am always tempted to venture into HO. This one is getting bookmarked. Great job.--Art Haule

ekkoautos on November 29, 2011:

thanks for sharing the steps of making lighting for HO Locomotive, the information is excellent

bandit28 on October 10, 2011:

This lighting looks superb and really brings the loco to life. I will be writing a similar how to guide for successful coach interior lighting soon useable with dc or dcc!!

Nancy Tate Hellams from Pendleton, SC on May 21, 2011:

Great instructions on Authentic looking lighting for your HO Scale Locomotive. Lensrolled to Palmetto Live Steamers Club.

Karicor on February 17, 2011:

Excellent instructions! Unfortunately, they come a little late for me - my first hubby was totally into HO trains and I enjoyed it too. It's a great hobby! Methinks I need to bless this lens :)

anonymous on December 09, 2010:

We have a display put on by the city at Griffith Park that needs this instruction.

anonymous on November 07, 2010:

Just saw an awesome HO Scale display today. I love the size of these model trains. They could have used your ideas on lighting...theirs was a little dim...the scenery was incredible though.

aldax on October 25, 2010:

Thanks for your tutorial. I have added lighting to my model tram after adding a dcc chip and it works well.

ZablonMukuba on October 10, 2010:

nicely done lens

bdkz on August 12, 2010:

Very cool lens!

Rhonda Albom from New Zealand on June 21, 2010:

Congratulations on your purple star!

LoKackl on June 19, 2010:

Wonderful resource! squidangel blessed!

LoKackl on June 19, 2010:

Wonderful resource! squidangel blessed!

Related Articles