SSPRR Run Room

Playing with Toy Trains

MTH Freight Truck with Operating ETD  30-76645

Repair End of Train Device flashing LED. 

Replacement Truck

Replacement Truck

Repair or Replace when LED malfunctions?

When the LED quits, MTH does not sell the replacement ETD.  The MTH repair part is the complete truck.
Replacement Trucks available are Trucks  20-89010 Yellow or 20-89013 White.

The following repair shows whether repair or Truck Replacement is best.
After repairing the ETD it's preferable to buy the replacement truck.  Repair is possible.

Original Parts

Original Parts

Opening the ETD may be optional if the LED tests okay.  Pull wire out of coupler to enlarge coupler wire way.
The ETD Housing Cover is a press fit onto the coupler mounted yellow ETD housing.
The LED assembly is carefully shaped for a tight fit in the housing.

LED Front LED Assemblies
LED Front with Shaped Assembly Evans Design LED Assembly at Top
Original LED Assembly at Bottom

Replacement Parts and Special Tools

Parts and Tools

LED assembly from Evan Designs (   The smallest flashing LED is red Part #52204.

Part #52204 = Slow-Flash-LED  Red  2.8mm red only   7-19 volt AC/DC with 30 gauge wire.

Misc. in stock:  Wire sleeve, liquid tape, heat shrink tubing, and 32 gauge tie wire.

Special Tools:
22 through 30 gauge wire stripper,  7/64 " drill bit for wire sleeve, and safety pin clamps

Enlarge Wiring Channel in Coupler

The MTH ETD wire insulation is so fragile it needs a wiring sleeve for protection.
Sleeving from low voltage multi wire signal cable works.
Enlarge the wiring channel with a 7/64"  bit.

Enlarge wireway Enlarged Hole
7/64 " drill bit in enlarged hole Coupler with enlarged hole

Install New LED Assembly

Prepare to Lengthen new LED Wire Between ETD and Circuit Board Box Location.
At this point test the MTH LED.  You may be able to leave it in place for the Evan Design circuit.

Prepare Wire


ETD Wire into Sleeve Clamps
Insert sleeve in coupler followed by ETD wires. Slip heat shrink over wires and solder assembly wires together with correct polarity.  Clamped circuit box in place helps gauge in line circuit position.  Test circuit with 18V.
New circuit fits in the box at an angle.
It may be easier to secure new heat shrinked circuit without the Circuit Box.

Assemble and Install Truck

Assemble Truck Truck Spring Tools
The fine wire holds the truck springs while inserting with tweezers.
The toothpick is used to apply liquid tape as needed.
Truck Tom Truck on Bottom Plate

Repaired and Running
Handling the ETD during repairs broke the antenna.


The MTH LED circuit creates a flaring blinking LED.  The Evan Designs circuit just flashes.

See Video with Flashing on Test Track. Video can be viewed with Windows Explorer browser.

MTH Circuit Board Removed

CB Top CB Capacitors


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