SSPRR Run Room

Playing with Toy Trains

Upgrade MTH F3 ABA with FT ABA


My Protosound 1 ABA F3s had been on my bad-order shelf since they died a couple of years ago. The A unit had 2 motors and the B unit (added later) had 2 motors synchronized with the A unit .  An upgrade to Protosound 2 required a PS2 Upgrade Kit and a Slave Kit to control the 4 motors. Since I haven't been able to purchase the slave kit I located a Premier PS2 FT ABA set with 4 motors at a reasonable cost. Each FT A unit had 2 motors and the trailing FT A unit had 2 motors and the Slave board.

 Step by Step Conversion Process

Run the PS2 FT ABAs to be sure all components are working.


Conversion Process and Photos

Remove shells to see how much work is ahead.

Start with A trailing units and B units:  Swap coil couplers.  The big hole in the top of the Silver Pilot needs to be enlarged for coupler plug and wires. Use a Unibit and enlarge the hole to 3/8".


                On FT A trailing unit, unplug smoke unit and save for another project.  Remove 2 motors and circuit boards (slave and lighting).


To remove and add lamps to light brackets in the F3 A units, the F3 A sockets must be removed.  Unplug lighting board from FT trailing A slave board. Cut green and red wires that go to contacts for red lights in shell.  Remove F3 A lighting circuit board. Drill mounting hole in the F3 A for FT A lighting board. Drill a #39 hole between the 2 old mounting holes. Tap the #39 hole with a 3mm - 0.50 tap.  Mount new board and lamps. Plug in coupler.

All units open with FT parts in F3 A Dummy.


Remove the wiring harnesses including plugs and connectors from the FT B unit.

F3 B unit ready for swap.

Strip F3 B unit.  Note routing for FT wiring harnesses.

Mount FT trailing A slave board and FT motors on F3 B unit. Drill and tap hole in base plate if needed.

The plug from the FT A Trailing lighting board harness will be plugged into the F3 B Unit. Cut off the plug leaving plenty of wire to tie into harness from the rear of the FT B unit.  Splice the cut off harness wiring from FT A trailing lighting board to the plug that goes into the front harness socket stand of the FT B unit. Secure the stand to the F3 A dummy and plug in.

Convert that FT harness circuit board socket to a free hanging socket. Trim the socket circuit board and  protect the trimmed circuit board with Heat Shrink tubing. Mark top of socket with white tape or paint.  Do final routing of harnesses between B and trailing A units after slave board is mounted on F3 B unit.  Plug F3 B unit rear harness into circuit board.

The pickup rollers with red wires should be removed from the trailing/dummy F3 A unit. The black chassis ground wires can also be removed.

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