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Discussion Starter #1
Hello all,

As a quick follow up to my previous post (http://www.modeltrainforum.com/showthread.php?t=132026) I ended up acquiring two MTH motors/motor blocks, and separately bought TMCC electronics. I got a cruise commander and sound commander (with Dash-9 sounds), and the engine looks, sounds, and runs great!

When I installed the electronics I used these LED's for headlights, two to a headlight, wired in parallel:
https://www.amazon.com/gp/product/B06XK2CK8P/ref=oh_aui_detailpage_o03_s00?ie=UTF8&psc=1
When I did the installation I only had access to a loop of track and a postwar Type Z transformer. Everything worked perfectly. Now that I'm home and have my legacy system set up, the headlights no longer function. They will occasionally flicker on for less than a second, and blink erratically when I program the engine. I understand the headlight is an indicator for TMCC signal strength, but could I have such lousy signal that the headlight is completely off?

To eliminate some variables, I do have full control over the locomotive even with the headlight off. All my other TMCC and legacy equipped engines have no signal problems. I use two transformers, a CW-180 and a Postwar KW. No difference between the two operationally. When I disconnect the Legacy system and run the engine conventionally with both transformers, the headlights work again.

Any help is appreciated!
~Vigs
 

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LED's have polarity, did you try reversing their connections? The red lead should go to frame ground and the black lead to the headlight connection.

The reason they work in conventional mode is the R2LC outputs full wave AC for conventional, but only half-wave rectified AC for command operation. The R2LC lamp outputs are negative in respect to frame ground.

Swap the leads and happiness will again fill your train yard. ;)
 

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Discussion Starter #3
And that did it. Interesting that it has AC and DC outputs for different modes, I never would have guessed that. I thought it was always DC output.

Thanks for the help Gunrunner!

PW4006-1.JPG

PW4006-2.jpg

~Vigs
 

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Actually, everything is mostly AC based. In command mode the lights are half-wave AC negative going, the smoke output is half-wave AC positive going, and the coupler outputs are track AC. In conventional mode, lights and smoke are full-wave track power and of course you can't operate the couplers in conventional mode.
 
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