Williams Cab Forward 7002

Someone should have the instruction sheets - I do not, but I am very familiar with the Williams/Samhongsa brass steamers.

They are all simple machines; the wiring is straightforward (there is not much in these engines) and following the wires, plus using a test meter, should tell you everything you need to know.

Mechanically, disassembly is also usually a matter of common sense.

I do not recall any electrical "schematics" in the Williams instruction sheets, and the disassembly instructions are pretty basic.

I have upgraded several Samhongsa (Wms/Weaver) brass steamers to ERR; pretty simple process in general (I do only basic Cruise Commander, coupler, and usually sound).

The antenna situation is usually the most tedious part; sometimes it takes some fiddling. (This is why I like plastic coal loads for the antenna - Williams used real coal, unfortunately, and your cab-forward is an oil-burner anyway).   

I owned one of these locs and, yes, the wiring is straightforward.  No mysteries, drama, or curve balls.  I, too, do not recall any wiring schematics.

If you're upgrading to TMCC, the original wiring will be of little use, right?  My first step with an upgrade like this is to rip out 90% of the original wiring.  I may leave stuff like class lights and markers if they're already LED's.

I've never seen the original wiring, but there is only four wires from the tender to the locomotive.  Two for the motors on the outside pins, and track power and frame ground on the inside pins.

D500 naled it pretty much. VERY simple wiring. And John also hit it as converting it to TMCC will require almost all new wire. So the instructions not much good. Mine came w/o any or I'd scan them. But I work on it w/o any info fine. 

Having done this with my cab forward, there is nothing to it. The Err loco to tender plugs are entirely useable. .Locate the two motor wires and the hot and common AC wires through the loco to the plug, note their respective positions on the plug. Working first with the motor wires notice their corresponding position on the tender plug, cut and wire into the TMCC unit. Then do the AC.  All the guts in the tender go leaving you with the rear tender light wiring only. Doing it this way the smoke unit and the engine lights remain in play as they are joined into the motor wires and AC wires.

Take your time and look carefully and it is easy.  The ERR instructions are very clear. Your biggest challenge is isolating the tender shell from the tender chassis. This requires ordering a special grounding tape and soldering the antenna wire to the tender shell.

If you feel this beyond what you wish to do. Ship and pay someone to do it. It helps if you have done some installs.

Ron H