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Airwire and TCS FL4

2969 Views 18 Replies 8 Participants Last post by  bdoane3941
I have a USA SD70 that I did my first r/c, battery,and sound install on. The airwire install went so easily, I thought I would press my luck and add additional lighting functions with a TCS FL4.
I first disconnected the phoenix p5. Then I installed the FL4; connected ditch lights (green and purple wires), front headlight (pink wire), and rear light (brown wire). Lights are all LED's and they all have resistors. All CV's were changed to program ditch lights and rule 17 (dimming) for front and rear lights. Each function button on the airwire tx worked properly.

The problem is when the lights dim, they flicker.

When the ditch lights are on full intensity they are fine (steady). When I press Fn2 to make them alternate, as each one dims and then gets brighter they flicker.
When the headlights are on full intersity they are fine (steady). When I press Fn4 to dim them, they flicker at the dim setting. When I press Fn4 again they go back to full intensity and they are steady again.

The FL4 is grounded to one of the weights in the loco.

All testing has been done on the bench and the motors have not been turning.

Is it normal for the FL4 to flicker when brightness is anything but full intensity?
If not, any suggestions how to stop the flickering?

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I see 2 possible problems.. I do not think the FL4 should be grounded.. The other issue could be you are dropping the voltage on the LED's to low.. May be a CV setting or the resistor is to big.. Other than those it should work fine..

I noticed a little flickering in the MARS light function. I han no problem at all with the dim function of the headlight.
There is no need to attach the ground wire of the FL4( blue wire, correct?) However, if you have isolated the wheel pickups for your Airwire install, then you may not really have a ground anyway, as the loco chassis is not connected to any of the Airwire circuits. If you actually do have a ground( check with meter), then you need to address that as it is a potentially damaging condition for the decoder.
What value resistors do you have. Move them down a bit- if 680 go to 560 or 470. if 470 go to 330 or similar. Try one first .

I put a video together to show what is happening. http://www.meltedchip.com/video/train/flicker.wmv
First you will see the headlight, out of the nose. The Fn button is pressed when it dims and flickers, it is pressed again and the light goes back to full intensity.
Second are the ditch lights. Same sequence as headlight.

I started with 750 ohm to 500 something ohm to 470ohm to 270 ohm. All with same results.
I also disconnected the "ground" wire.

Could it be interference of some type?
I have not put any type of noise suppression on the motors. Would that matter?

I am including the CV's that I modified..

CV 51=10
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I strongly suggest that you send a not to TCS and ask them. I find them very responsive and helpful.
The blue wire is not ground, it is common. DCC decoders use a POSITIVE common, the "outputs" are actually inputs, they are actually open collector inputs that go to ground when "on" thus the need for the common to be positive.

Regards, Greg
Blue is the correct colour for the polarised DC postive from track power to supply accessories like lights.

Others don't think so.

Two of the Phoenix 10 pin P5T output cables are blue. BOTH are connected to the pcb ground.
Perhaps you would care to lend your weight to approach Phoenix to get it right?

As a matter of interest, and a serious question. Can you tell me what the correct colour wiring is used for the DCC pcb common ground?

Is it Black with a white trace?

The Black/White wire on the TCS decoders is gound for there low voltage regulator circuit for LED lighting..

Unless I missed it I didn't see what battery voltage you are using. Calculating the resistors needed is also dependent on that battery voltage.
I wired just like the manual.

Blue to positive to led to resistor to function wire

red and black to airwire terminals

Black/white to ground

Battery Voltage is 14.8
I have tried 1/4 watt and 1/2 watt resistors.
They all have the same effect.

I have contacted TCS. I am waiting for them to get back to me.
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My instructions say nothing about connecting the black/white wire to anything.

As for resistors, I would suggest that you use a 620 ohm (or slightly larger), 1/4 watt resistor for a single white led. This will give you a current draw of about 20ma.
I don't want to get off subject here,but there is a point to be made. Ben mentioned that he disconnected the P5 before programing the FL4. This is an important point. CV's 49-53 are duplicates between the P5 and the FL4. Without disconnecting the P5,in Bens case CV51-53 would have altered the programing in the P5.
I picked up a second fl4 from a different retailer. It had slightly different packaging.
Same results.

I talked to TCS and we could not come up with a solution so, they are testing 2 units at their shop, making sure they work, and then sending them to me.

OK, So... the brand new, direct from the manufacturer decoders produce the same result.

I checked with resistors from 240 ohm through 1.4K ohm.

Any other ideas?

Hey Ben, did you ever get the flickering light problem figured out. Been planning to get some fl4 decoders but been holding off cause of the problem you've had.
Later Bull
I installed an FL-4 in an AirWire equipped engine. One function is for MARS light, one for number boards and the other 2 for the headlight, one for forward bright and the other for dim in reverse. The dime headlight works just fine. I did notice some slight flickering with the MARS light but not enough to be objectionable. There is no flickering with the dim headlight. I did not hook up the black/white wire at all.
thanks for info Bill. I am going to have a qsi decoder and 2 fl-4's in each engine so I have seperate control of front and rear headlights and front and rear ditch lights. Going to have step and walkway lights also.
No, I have gone through 4 FL4's and 2 airwire decoders. I continue to get the flickering.
I decided that I could live with it and closed it up.

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