Converting an American Flyer loco to DC operation

The American flyer will run on AC or DC directly as made. The down side is the E-unit in the tender or boiler will not function 100 percent of the time. Occasionally they will "hang up" and create a condition called "tender thumping". The E-unit can be locked in a specific direction. When running DC the E-unit can be magnetized which can hinder or eliminate reversing capability which could require de-magnetizing or E-unit replacement. Changing the system to "DC only" eliminates the directional problem due to e-units. the only condition required is the power going to the track must be DC and reversible as well. DPDT switch after the added (10A minimum) rectifier between the AC transformer and the track solves the problem. (Calculate rectifier capacity by using 4A times the locos that will be running at one time)

1) Screwdrivers, both cross point (Phillips) and regular point
2) Wrench for Wheel Driver Screws. Screwdriver style socket is recommended to avoid scratches.
3) Soldering iron and rosin core solder
4) Heat shrink tubing
5) 6 amp min to 8 amp max rectifier for loco Bridge Rectifiers | Diodes | Electronic Components Distributor DigiKey
6) Plastic sandwich bag for the removed parts, they are replaceable to return the unit to factory specs. Label the bag with a permanent marker for future reference
7) JST connectors for future disconnect of the loco tender combination (optional)
8) Couple feet of 20-24 gauge wire
9) Cradle for loco to disassemble without damage (optional)

Step 1) Tender disassembly Remove tender from loco. Most can be removed by unplugging and unhooking or unscrewing the drawbar. Remove the screw holding the e-unit to the chassis. Unsolder the wires from the e-unit to the tender chassis
Step 2) Tender upgrade Solder 2 wires from the rivet head on the tender log enough to reach the loco plus about 3 inches. Some may be trimmed off later. Always use same rivet for positive lead allowing direction to be the same on all locos. Space connector to be hidden below the engine cab preventing wire issues in turns by adding wire to the lead to the rear rivet. Use heat shrink tubing over any splice preventing short circuits. Coil wires at rivets allowing truck movement without wire stress causing future breakage (JST connectors can be used to allow future loco-tender disconnect or swapping without a soldering iron) Reassemble tender and place to side
Step 3) Place loco in cradle with wheels up. Remove boiler assembly allowing the motor and chassis to be worked on. (see loco disassembly in cleaning and servicing) Unsolder tender plug leads at loco to field wires and connectors for brush leads on rear of loco motor. Place wires to side or in zip-lock bag for return to original should it be desired. Note if the reversing unit is removed, weight may need to be added for conductivity to rail.
Step 4) Place rectifier on the armature end cap. Positive toward right side. Solder positive lead (+) of rectifier to right field wire. Solder negative lead (-) of rectifier to left field wire. Solder jumper wire from left AC input (~) to left brush clip or terminal. The two open terminals (right ac rectifier input (~) and right brush clip or terminal) are motor DC inputs for the wires from the tender. You may wish to keep things the same when modifying. Right rail pickup always goes to specific input to keep locos direction consistent.