A class decoder

[Thomas]

I have a IRM "A" class locomotive. The sound chip is not responding to any commands. Checked it out and it is fried. I would like to instal a non sound decoder but to date any ones that I put in will not run the lighting correctly. It will move forwards and backwards fine and the ditch lights work. But that is it. I wonder do you have to get a decoder from IRM and if so what one? 

Thanks in advance for any advice.

[irishthump]

On 13/8/2025 at 6:11 PM, Thomas said:

I have a IRM "A" class locomotive. The sound chip is not responding to any commands. Checked it out and it is fried. I would like to instal a non sound decoder but to date any ones that I put in will not run the lighting correctly. It will move forwards and backwards fine and the ditch lights work. But that is it. I wonder do you have to get a decoder from IRM and if so what one? 

Thanks in advance for any advice.

Have you considered going back to the seller with the decoder? If it was faulty they might help you out.

[Thomas]

This is a model sent to me for repair. The oner stated that the track got shorted while operating it on his railway and now wants a non sound decoder.

[Mol_PMB]

This is not my area of expertise.

However, I know that there was a modification needed to the wiring in the A class to make some lightling functions work - I think that may have only affected the cab lights though? @Fowler4f knows more and may be able to advise?

Also, is the function mapping on your new chip matched to the A class functions? It ought to be possible to re-map the functions on any/most chip types - again, not my area of expertise. You shouldn't have to buy an IRM chip.

On the other hand, an IRM chip should come set up correctly in the first place, so it may be the easiest solution. But at present, only sound chips seem to be available for the A class:

https://www.accurascale.com/collections/cie-a-class

Sorry this isn't as helpful as it might be.

[DJ Dangerous]

27 minutes ago, Mol_PMB said:

This is not my area of expertise.

However, I know that there was a modification needed to the wiring in the A class to make some lightling functions work - I think that may have only affected the cab lights though? @Fowler4f knows more and may be able to advise?

Also, is the function mapping on your new chip matched to the A class functions? It ought to be possible to re-map the functions on any/most chip types - again, not my area of expertise. You shouldn't have to buy an IRM chip.

On the other hand, an IRM chip should come set up correctly in the first place, so it may be the easiest solution. But at present, only sound chips seem to be available for the A class:

https://www.accurascale.com/collections/cie-a-class

Sorry this isn't as helpful as it might be.

Roads and Rails posted this video on swapping the cab lights and shunting lights, to make the cab lights directional, and have the correct shunting lights:

 

 

[Blaine]

6 hours ago, Mol_PMB said:

This is not my area of expertise.

Sorry this isn't as helpful as it might be.

So why bother even replying? 

[Mol_PMB]

Just now, Blaine said:

So why bother even replying? 

Because at the time I did, no-one else had provided a useful reply and I thought that some of my links might be useful even if they weren't the full answer. At the very least it bumped the thread and DJD then responded.

I apologise again.