Hello All: Yesterday, I was at the nieghborhood hobby store. I was talking to the owner about adding reverse lights in my locomotive. He showed me a package of them. A single light would cost almost $10.00. I thought that was too much. I examine it closer. What I saw how it works amazed me! PLus, I should have known better. Here's how they are made. They used a diode and a light bulb. "Damn". I said to myself. You can get a package of 2 diodes for under a dollar at radio Shack. Lights, just the same. A little while ago, I was going through my Ham Radio junk box. I found some diodes. I took them out. I took off the locomotive from the tracks. With some jumper wires and turning the power to the tracks. There was no light. Then I put the power pack in reverse. "I saw the light. And I was please!" So my advice is. Get yourself some diodes and lights for under $5.00 and get those locomotives with reverse lights! I tried this with a signal light. It works but the lumination of the lamp is equal to what the power pack is putting out. I think adding a relay to add a constant voltage will help. See you all later, Andy Tech note: "WHAT IS A DIODE?" Think of it as a one way street. The voltage/current can flow ONLY in one direction. Reversing the voltage/current, will turn it off.