ESU V4L problem

[RichardSpoors]

I have an 0 gauge locomotive that has been built with a live chassis and insulated wheels on one side. It is fitted with an ESU V4L decoder. I can program CVs and the sound file works whilst the loco is at rest. When power is applied, the decoder cuts out. I have tried another V4L and the same thing happens. I have retained the track input wires and wired the decoder to an identical motor on the bench, and everything is fine. Can anyone suggest what my problem is? The loco runs fine on DC with no shorts. Does DCC not like a live chassis, even though it's insulated?

Thanks for your interest.

Richard  

[Hamburger]

Is there any connection between motor and chassis, even by (conductive) mechanics, inductance or capacities?

How did you wire up U+?

Any connection between bulbs etc and chassis?

 

[RichardSpoors]

There must be something! Just tried a Zimo decoder with the same problem. There is a copper wire holding the motor down. U+ is not connected. Just the track input, motor, and speakers. No lights etc. In the morning I'll remove the copper wire. 

Thanks.

Richard

[Crosland]

If you can program, etc., while the loco is at rest, and assuming this is on a programming track, not on the main, but it cuts out when running then it is most likely an (electro-)mechanical problem. The motor is energised briefly during programming and any shorts should be detected by the system.

 

Does the decoder itself cutout or does it just lose contact with the track? Try a little downward pressure whilst running slowly.

 

What sort of pickups do you have from the live chassis and the insulated wheels?

 

Are the insulated wheels causing a short, e.g., bogie or pony truck wheels touching chassis, valve gear shorting insulated wheels to chassis, driving wheels touching brake rigging?

 

The motor casing may be connected to one of the brushes and the wire around the motor could be an issue but, if it's causing a short, programming should fail.

 

Have good poke around with a continuity tester and verify the motor brush connections really are completely isolated.