Zimo MX645R issue with lights

[badgerV8]

Hi folks, got a weird issue with a Zimo MX645R that I've just fitted to a Heljan Class 26.

 

Decoder powers up fine, loco movement is good (but reversed directions), sound is good. Until I turn the lights on!!!

 

The lighting switches ends as I select forward or reverse with the loco not moving, but in the opposite sense to the drive, i.e. tail lights forward and headlights at the rear. That in itself is a reasonably easy fix, all I need to do is swap the motor wires over, as switching direction via CV29 also alters the lights, leaving them still the opposite sense to the drive!

 

My problem however, is that as I move forward, the tail lights that are switched on at the front, start to dim then pick up brightness with speed, whilst the headlights that are on at the rear go out completely.... movement backwards with the lights on is perfect, but movement forwards requires a far greater controller input to move than with the lighting turned off. I have to input a speed of around 20mph to get it to crawl at 5mph, backwards direction is fine. Turn the lights off, all is back to normal and good!

 

Anyone got any ideas with this?

 

Cheers.

[Nigelcliffe]

First check is that the speed steps in CV29 match the speed steps selected in the control system.   If one is set to 14 steps and the other to 28/128, then lighting weirdness can be a symptom. 

 

Once that check is done, other possibilities can be investigated. 

[badgerV8]

Hi, the speed steps will be as programmed by the vendor, only thing I've done is alter the top speed CV5 from 001 (flat-out, way too fast!) to a more realistic 120, and the mid CV6 to 070. Oh, and turned the volume down with CV266. What do you mean by the speed steps selected in the control system? I use Railmaster to control the layout, every other loco (over 20 of them, some with Zimo, some with ESU) all work correctly with no issues.

 

It's now behaving speed and direction wise, but the lighting is only operating as it should in one direction only (reverse), with head and tail lights working correctly, but when I select forwards, all the lights are on at both ends. Now, here's the weird bit - it ONLY does this when the sound is turned on, if the sound is off, the lighting operates correctly, both directions..... 

 

It seems I can have correctly operating lights, or sound, but not both at the same time..... All wires have been checked and re-checked as well, there are no shorts or bad connections.