I contacted Digitrax Support about the problem and was told it was a bad decoder, to ship it back.

So I guess that takes care of that.

Bad deal to get a lemon first time trying a mfrs. product, but it happens.

Live and learn, what? 

Thanks again for you interest and suggestions.

regards,

Terry

Seems I was mistook.  

With the rear headlight wire (white) disconnected, I still have constant, no OFF light.

According to the manual for the decoder, in either case, F0 should be ON/OFF.  
It says CV29 default = 6, but it reads 39; if I set to 6, no motor, constant light; reset to 39, motor but still constant light.

Anyone know what's going on?

Thanks.

Terry

Well, alrighty then!!  

Turns out, somebody missed the wire color conformity boat.

Decoder blue to lightboard white/decoder white+yellow to lightboard blue gives constant lighting, but no OFF.
If decoder white only to lightboard blue, then fwd light only, directional w/OFF.

So another great DCC mystery solved!  
Maybe someone else can avoid the brainstrain if they read this.

Thanks for your suggestions and interest, tweetsieengineer!

Terry

I reset w/no change.
Other than when I applied direct DC, the light hasn't lit at all.
I get all lights on when programming others.

Wires are spliced and I resoldered to be sure no cold joint.
I'll ck voltage at the splices w/it running - seems I should read something if the output is good.

More later. 

Terry

Thanks tweetsieengineer -

F0 should do it on my Power Cab, but nada.

I tried it on DC also, runs but no light.

Low voltage DC directly to the lightboard and the light works fine, so it's ok.

I don't have a decoder tester - any ez way to check (with a VOM mebbe?) if the decoder output is bad?

Terry

Hi all -

I'm new to the forum and new to DCC.

I just installed a Digitrax DZ-125 in my 2-8-0 which ran fine on dc, light and all.
BTW, this decoder fits nicely after trimming the shrink close to the board opposite the wires.
Should fit any others with the same or more room in the boiler.

Since the decoder install, it runs fwd/rev, programs, but I have no light.
Default is directional lighting, the lightboard is connected blue/blue, white/white so it should work as before.

Seems I ran across mention somewhere of a resistor needs removing, mebbe?
If I get this sorted out, would decoder white & yellow to lightboard white give light-on all the time?

Any thought/suggestions appreciated.

regards,

Terry