This installation is for a HO-Scale Athearn Ready-to-Roll CF7 using a TCS WOWDiesel-EMD-KA Decoder and was performed by TCS.

Important Soldering Tip:
Please do not use any flux either liquid or paste on the mother board. It will damage it. Use only Rosin core solder approved for electronics use.
We recommend to use only Kester "44" rosin core, SN63PB37, .015" diameter, part number 24-6337-0007.
This can be ordered from Techni-Tool under Techni-Tool part number 488SO157

HO-Scale Athearn Ready-to-Roll CF7 prior to WOWDiesel-EMD-KA decoder installation

In order to install the decoder we must first remove the shell. Remove both screws securing the coupler boxes and remove the assemblies from the chassis.

The shell will now slide up and off of the locomotives chassis.

With the shell off, we can now see the factory light board. For this install, we won't be using any of it, so we can remove the factory light board completely.

The above picture shows the factory light board removed.

In order to keep wire joints down to a minimum, desolder all pick-up and motor leads from the chassis. We will solder the leads from the 9-Pin harness directly to these points in the next few steps.

To be able to desolder the factory wire leads on the motor and chassis pick-up, we must remove the motor temporarily.

This is easily done by removing the four screws located at the bottom of the fuel tank.

With the motor removed, we can desolder the factory motor lead and solder on the gray motor lead from the 9-Pin harness.

With the motor still out, we can also solder on the black lead from the 9-Pin harness to the chassis pick-up tab.

With the black and gray leads complete, we can now secure the motor back to the chassis. Next, solder on the orange and red leads from the 9-Pin harness.

As seen in the picture above, the right rail pick-up will need a jumper between the two pick-up points on the trucks.

Next, we will work upgrading the lighting in this locomotive.

The stock lighting from Athearn has their 1.5v bulbs, which produce a weak headlight and burn out with only a fraction of the hours on them compared to LED's.

Therefore, we decided to upgrade our lights to LED's. Since the stock bulbs rest inside the light housings, we need to frabircate light tubes for the LED upgrade.

Using .06" diameter fiber optic tube, we created our own light channels. We simple cut about (4) 1/2" pieces, which we then crowned one end with a small torch.

If you don't have access to a torch, a lighter will work. Make sure not to place the tube into the flame and burn it. All we want to do is create a small lens head.

Once we have crowned all four tubes, we then shortend them to about 1/4" long, trimming off the non-crowned end.

Next, insert each tube from the outside of the locomotive. Each crown should fit nicely into the headlight bezels as seen in the photos above.

Once the lens' are in place, a quick dab of CA glue on the inside will help keep them in place. The finished rear lights can be seen in the above picture.

With the lens' complete, we can now work on the LED's to light them. We used two 3mm warm white LED's and attached our wire leads to them. We then insulated each solder connection with 1/16" heat shrink tubing. Next we used 1/4" heat shrink tubing to shroud the LED and prevent any light from bleeding into the locomotive. As seen in the photo above, the lens' of the LED are flat. This can be accomplished carefully with a file or some sand paper. In our case, we happened to have some flat top LED's for our install.

Once the LED's were prepped, we then glue them with CA glue to the dual lens' of the front and rear lights. The above picture shows the completed front headlight.

Next, we then soldered our LED leads to the funtion outputs on the decoder.

Make sure to include a 1/6w 1k Ohm resistor in series for each of the LED's.

With lighting complete, we can now mount the decoder, KA2 and speaker.

In our install, we used our 16X35mm speaker and mounted in the rear of the locomotives shell where the radiator fans are.

On this model, the fans happen to be see through, which provides a great opening for audio to come out of the top of the locomotive.

Prior to installing the speaker, we also added 4 side walls to the speaker. This can be accomplished with styrene or a 3d printer if available.

Please note: Audio is produced equally from both the cone and driver side of the speaker. Therefore a complete enclosure around the speaker will result in poor audio quality and lower volume.

With all three components mounted, we can now close up the locomotive and reinstall the coupler assemblies.

You have now installed a TCS WOWDiesel-EMD-KA decoder into your HO-Scale Athearn Ready-to-Roll CF7.

Other solder tips: When stripping wire, only strip a tiny little bit of the insulation. Strip no more then a 1/64 of an inch. When the wire gets tinned with solder the insulation will shrink back more. Try to not expose any more wire then half the length of the solder pad at most. In no case should solder or exposed wire wire ever be outside the boundary of the the solder pad you are attaching a wire to.
Click here for important information on properly Stripping and Tinning wire

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