Cab Lighting

[Alan564017]

I have two MM 071's, both fitted with MM 6 function decoders, neither were run for a while. As soon as the wheels touched the track, both cab lights lit up. When moved the cab lights went out, all functions operated as normal including the cab lights. I found this a bit odd, is there a possible underlying problem?

[Garfield]

Not sure if it's down to settings that can be changed, but in real life the cab lights would be switched off while the loco is moving...

[Noel]

Not sure if it's down to settings that can be changed, but in real life the cab lights would be switched off while the loco is moving...

 

Check the two dip switches under the loco body normally used to set the lights when under DC operation, are at their factory default settings in case this is effecting their startup state when using DCC.

[irishthump]

Try resetting the decoders to factory settings by entering a value of 8 to CV8.

 

Decoders can sometimes behave peculiarly if they have'nt been run for a while.

[irishthump]

Not sure if it's down to settings that can be changed, but in real life the cab lights would be switched off while the loco is moving...

 

These decoders can be programmed to make the lights behave like this. As you say, probably more prototypical the way it is.

[Noel]

These decoders can be programmed to make the lights behave like this. As you say, probably more prototypical the way it is.

 

That's correct - dark cockpit needed for driver. I don't bother with cab lights anyway for that very reason. They look naff anyway, far too bright even when dimmed and they have a blue tint.

 

For that reason a less expensive four function decoder is perfectly sufficient for all MM locos. For non-sound use a quality decoder such as Lenz Silver+ 10321 at €25ea will drive 071/201 ok. The Bachmann 36-557 should also be fine if you can get the later revision, early versions had intermittent issues with some DCC controllers. The MM0004 (201) and MM0005 (071) are just €35 versions of the ESU LokPilot V4 DCC chip which can be bought for €31ea in Germany, mind you it might be less expensive to buy retail over the counter here than pay postage from Germany if only ordering one.

 

PS: Beware the LokPilot Fx V4 is only a function decoder and has no motor drive.

[Garfield]

That's correct - dark cockpit needed for driver. I don't bother with cab lights anyway for that very reason. They look naff anyway, far too bright even when dimmed and they have a blue tint.

 

For that reason a less expensive four function decoder is perfectly sufficient for all MM locos. For non-sound use a quality decoder such as Lenz Silver+ 10321 at €25ea will drive 071/201 ok. The Bachmann 36-557 should also be fine if you can get the later revision, early versions had intermittent issues with some DCC controllers. The MM0004 (201) and MM0005 (071) are just €35 versions of the ESU LokPilot V4 DCC chip which can be bought for €31ea in Germany, mind you it might be less expensive to buy retail over the counter here than pay postage from Germany if only ordering one.

 

PS: Beware the LokPilot Fx V4 is only a function decoder and has no motor drive.

 

Not really addressing the OP's issue there, Noel...

[irishthump]

Check the two dip switches under the loco body normally used to set the lights when under DC operation, are at their factory default settings in case this is effecting their startup state when using DCC.

 

That's unlikely, Noel. Those switches are basically on/off and would'nt really be able to affect the cab lights the way the OP has described.

[Noel]

That's unlikely, Noel. Those switches are basically on/off and would'nt really be able to affect the cab lights the way the OP has described.

 

Ok, your suggestion of a decoder reset CV8=8 looks like the best option.

 

Loco address will revert back to default of 3.

[Alan564017]

thanks for the replies, everything is working fine, so i'll leave well enough alone. It was an odd occurance that never happened before.

[irishthump]

thanks for the replies, everything is working fine, so i'll leave well enough alone. It was an odd occurance that never happened before.

 

So did you need to perform the decoder reset or did the problem go away on it's own?

[Alan564017]

I left well enough alone, so far so good

[irishthump]

I left well enough alone, so far so good

 

I'd be very wary of not looking into it further. There could be a problem with the PCB or maybe a loose wire somewhere in the loco. Although the fact that it happened in both locos would make a PCB fault more likely.

Also, if the locos were'nt ran for some time were they stored in a cold/damp environment? That could cause a buildup of moisture.

Personally I would open the loco and have a look, the body is tight fitting and could trap a wire against the chassis.

Also check how the decoder is sitting on the PCB. Esu decoders tend to sit a little high which can result in metal on metal contact when the body is placed on top.

Edited September 14, 2016 by irishthump