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Converting A Lima Model To DCC (Fitting a DCC Decoder – Hardwiring a Decoder)

Converting A Lima Model To DCC (Fitting a DCC Decoder – Hardwiring a Decoder)

Converting a Lima Diesel Model To DCC


In this article we take a look at converting a Lima diesel model to DCC (Digital Command Control) by hard wiring a DCC decoder / chip into it. Most Lima diesel models are fitted with a ringfield type pancake motor, though the Lima class 67 & class 20 are fitted with can type motors. The decoder i’m fitting in this Lima class 60 model is a Gaugemaster DCC27 OMNI Decoder – 21 & 8 Pin Decoder which can be found in the Scale Model Scenery shop here:


Also available in a pack of five as well. This decoder will fit both 21 pin & 8 pin DCC ready models, DCC Ready means ready to be converted to DCC by means of fitting a DCC decoder to convert it to DCC. The 8 pin harness has decoder plug on it which is handy for swapping the decoder fitted with a similar socket to suit said plug. The photo below shows the plug on the harness & decoder with plug socket.


If you’re using a decoder with a 8 pin  harness it’s worth fitting a 8 pin harness with plug socket like the one shown below. It’s just a case of hardwiring the harness rather than the decoder if using the harness.

How to fit the decoder

First off make sure your model runs fine on traditional analogue control. Before converting to DCC it may be worth while servicing the model to make sure it’s running in tip top condition.

  • Remove the loco body.


  • You’ll see two wires from the pick ups to that connect onto the motor brush retaining plates. We’ll unsolder these two wires from the motor brush retaining plates.


  • Remove the suppressor (marked by the yellow circle in the left photo below) that sits between the two motor brush retaining plates.


  • Once the suppressor is removed unsolder the the two pick up wires as shown below in the photo.


  • Next remove the 8 pin plug from the decoder harness.


  • The four wires you need to use are the Grey, Black, Red, Orange wires. Unless your fitting lighting these are the only wires from the decoder that are need. Strip the end of the wires & solder tin the exposed wire ends.


  • Next solder the four wires as shown in the photo below. The orange & grey wires these go to the two motor brush plates as seen below. The red & black wires go to the two unsoldered pick up wires. The black wire to the short pick up wire on the left & the red wire to the longer pick up wire on the right. Be sure to put some heat shrink over the soldered joints on the two pick up wires.

One way to remember which wire goes where: Red & Black To The Track – Red & Black to Pickup Wires

Orange & Grey To The Motorway – Orange & Grey to The Motor



  • Next plug the Gaugemaster OMNI decoder onto the harness as shown below.


  •     Next is to place the decoder where it’ll not foul the any moving parts or the body. Make sure the decoder is insulated from any other metal / electrical parts to prevent the decoder from shorting out. In the photo below the decoder has been secured using double sided sticky pads, & the wires taped up securely as shown.

  • Having fitted the decoder now place your locomotive on the DCC programming track.


  • With the locomotive placed on the programming track we now select read loco address on your DCC controller. This is to check that the decoder can be read or written to by the DCC controller. Select loco address read.



  • The DCC controller should now read the decoder’s address on the locomotive. If all is okay it should read address 3 which is the standard default address on any new DCC decoder. as shown below.


  • If the decoder address can be read & shows default setting address 3 place the locomotive on your layouts main track. Test run to make sure all works ok & that no wires foul the motor etc.


  • Once happy all is okay refit the body making sure that you don’t trap any wires as you replace the body.


And that’s it! Time to enjoy a running session…

Happy Modelling.

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1 Comment

  1. Ashvale

    I’ve converted many older Lima locos, they do benefit from being thoroughly service prior to fitting the chip of course. For my mind I strip the motor bogie down cleaning all the pickups and gearing as well as the motor itself. I usually also replace the carbon brushes and springs and rewire the internal wiring to add more pickups. As a final addition I also tend to add 2mm tower leds so they have directional lighting. They can run just as well as a newer model but they are always louder and you get that smell (reminiscence of youth perhaps!) that you just do not get with modern motors! I have remotored a few with cd drive motors too and they are a lot quieter. Alas I currently only have four limas – two the porterbrook specials (47/55) I replaced the chassis with Hornby DCC Ready versions.

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