This installation is for N Scale Walthers LL Proto N GP 18 uses TCS K2D4 Decoder and was performed by A.G. and N.G.
The upper three pictures show the Walthers LL Proto N GP18 with its shell on.
This picture shows the locomotive's chassis with its shell taken off and the original lighting board. Be careful as you take off the shell because it is difficult to remove and can be broken easily.
This is not a drop-in installation because there are several modifications that need to be done. First, one of the slots (circled in red in the above picture) is too small and needs to be filed in order for the decoder to fit. This is not an error in the decoder, it's just the way that the frames are. The decoder could not be made any smaller because of the other locomotives in which it fits.
After the slot is filed it should match the other half of the frame, as shown in the above picture.
After the decoder is installed you will have to slip the tab coming from the motor underneath of the clip from the decoder. The tab from the motor is too short, however, and will not hold underneath the motor clip. The only way around this is to solder a wire from the motor tab to the motor clip. The tricky part is that if there is too much solder applied the shell will not fit back on, and if too much heat is applied the plastic motor casing will melt.
In order to isolate the motor tab from the frame a small piece of Kapton tape can be placed on the frame, but make sure its not in the way of the shell.
Next solder a wire to the motor tab and to the top of the motor clip where it attachs to the decoder. BE CAREFUL that you don't apply too much heat to the motor clip on the decoder because it is only held in place by solder and may fall off. The motor clip needs to remain in place, because if it doesn't the shell will get caught on the tab from the motor.
This shows the top of the motor clip with the wire attached to it. DO NOT ADD TOO MUCH SOLDER. This will result in the shell not fitting on properly.
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
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