# led headlight always on



## paxton1958 (Feb 23, 2010)

Have a loco with headlight only. Wired led to white and blue wires from harness. Headlight always on regardless of throttle in forward or reverse position and when lights are turned off. All programming looks okay. Reset decoder to factory settings and problem continues. Was working okay with a different led but not after switching to another. Decoder is TCS T1. Any ideas on why headlight is always on?


----------



## mopac (Feb 24, 2011)

I would reset decoder 3 times in a row. Sometimes that works. Changing LED should not cause this. If reset does not work somewhere along the line changing LED caused a problem. Then I would redo the LED. Good luck. Maybe try the original LED.

There is a light button on your controller.


----------



## D&J Railroad (Oct 4, 2013)

I would take the locomotive, holding it at one end and bang it on the edge of a table like you would do with a base ball bat. If the LED doesn't light then, problem fixed.
Actually, I would check the wires again, were they connect to the decoder and to the LED. You may have the polarity of the LED reversed.


----------



## paxton1958 (Feb 23, 2010)

Have reset several times. No change. Redid leds with two new ones forward and reverse. Can control reverse with light control and goes off when in forward. Forward stays on all of the time. Switch decoder with no change. Wiring all seems okay.


----------



## DonR (Oct 18, 2012)

You can test the decoder by disconnecting the headlight
LED, then probe with your multimeter set to DC volts
the blue and white wires. Use your controller to 
set FWD or REV and lights ON or OFF. Meter should
go to zero when REV or OFF. If not, a CV needs to be
reset or decoder is defective.

However, I note that you say a change of decoder does
NOT solve the problem. If that is correct, somehow
voltage is getting to the LED other than from decoder.
Very carefully check that the white and blue wires are
not touching anything other than the LED and the
decoder. Do you have the Blue (+) wire to the long
LED lead? You also should have a resistor in an LED
lead. Generally the blue and white wires produce 
12 V DC.

Just in case you don't have one, here is the decoder
wire color code chart.

https://ncedcc.zendesk.com/hc/en-us/articles/204223929-Basic-decoder-wiring-diagram

Don


----------



## D&J Railroad (Oct 4, 2013)

I can't go by the wire color. I have to trace were the wire comes from.


----------



## Lemonhawk (Sep 24, 2013)

You might check the CV's that control lighting. Is there an option that keeps the forward light on all the time?


----------

