The good news ... IT WORKS! I took nearly 5 hours installing this decoder, and yes, it was my first. But then, when you are soldering on a wire connected to a $50.00 device, care seems to be in order. Here is how I did it along with some things I found out just a little late.
Review the instructions that came with the engine. First remove the steps, remember they slide under the MU hoses. Second remove the fuel tank, just grasp and pull gently straight down. Third, remove the two brass screws. Fourth, look just back of the coupler pockets, you should see a screw by each. This screw goes into the full size weight inside the shell. Just loosen them 2 or 3 turns. Finally lift the shell off, being careful of the grills and other delicate details.
I didn't catch on to the two screws holding the weight and assumed that the weight was pressed on, so after I removed the shell, and cut the wiring free, I pried it up. Doesn't seem to have caused any noticeable damage other than to my ego.
Once the shell is off, you will notice tape across the top of the weight, over the headlight, in the middle, and over the rear headlight. Remove the tape and the thin plastic covers and lift all the wiring free of the weight. I cut the lights and diodes off and then cut the wires feeding the front and rear trucks. You are now able to remove the weight from the frame, should be able to lift it off with just a minimum of force.
You will need a voltmeter set on Ohms. Mine has an audible alarm when it detects continuity, which is very handy. Place one of the probes on the front motor brush and the second on the frame. If you get any movement from the needle or any reading other than zero, the brush is electrically connected in some way to the frame. I was surprised when I got a reading because the Proto2000 appeared to be wired such that the motor was isolated. Investigation identified that the wire from the brush clip on the bottom of the motor, which is supposed to feed past the weight and then up a slot in the side of the weight had some of the insulation pinched off. It might have been from my less than graceful removing of the weight while the screws were still attached, but in any case check this wire to be sure. I also checked from the trucks to the frame, and anything else I could think of. But with the frayed wire repaired I found no other connections.
If you don't have the April 1997 issue of Model Railroader, you might want to get one. Keith Gutierrez and Lee Rayburn have written an excellent article on Decoder installation and the drawing of a typical Athern installation really puts all of this in context. (Thanks guys.) For the purposes of these instructions, Front refers to the Cab end. These instructions also result in the engine running long hood first as was the practice of the N&W. I'll note where to swap wires if your prototype ran the short hood forward. First, the Decoder will fit easily on top of the weight in the cab area of the engine. At the front of the engine, drill and tap a hole for a 2-56 screw inside the frame ledge by the front truck opening. Now wire the truck pickup tabs together;
Solder a wire to the top of the truck pickup tab at the rear (away from the cab)
Replace the weight, feeding the wire you just soldered up through the hole in the weight.
Feed the wire across the top of the weight to the front truck pickup tab and now solder that connection.
At this point I placed the Decoder on top of the weight and test fit the shell. (Actually, I did this step a lot). It fits. Solder the Black Left-Rail pickup wire to the 2-56 screw. Solder the Red Right-Rail pickup wire to the top of the front truck pickup clip. (If you want short hood first swap the Red and Black connections). Solder the orange wire to the top brush retaining clip. Solder the gray wire to the yellow wire on the GP-18 motor feeding up from the lower brush retaining clip. At this point I tested the engine on the DCS100 programming track. I then used alligator clips and masking tape to enure I kept all the clipped wires separate and using two 12 volt, 50ma bulbs, temporarily wired up the lights. Clip the decoder common Blue wire to a lead from each of the bulbs, clip the white wire to the front bulbs remaining lead and clip the yellow lead to the rear headlights remaining lead. I then tested this on the programming track. Satisfied, I cut the Decoder leads to an appropriate length, soldered all the connections, insulating each with 1/16' shrink tubing and then ran a final test. All the wiring will fit in the grooves in the top of the weight. I didn't want the front bulb laying directly on top of the wiring so I placed a piece of styrene, cut to size, over the wiring and then layed the bulb in the slot on the weight. I replaced the plastic covers over the wiring at the center of the weight and over the rear headlight, using electrical tape. Now, replace the shell, screws, and fuel tank followed by the front and rear steps and you are ready to run.
Go back to the DCC Page