Return to the BUILD

“Fit the circuit board that controls the lighting system to the underneath of the floor pan, then connect it to the wiring from the brake pedal and dashboard switches.”




  • 51A – Control Circuit Board
  • 51B – Small Cable Clips
  • 51C – Large Cable Clips
  • 4x CM screws (+2 spare)
  • 4x MP screws (+2 spare)
  • 1x OM screw (+1 spare)

Materials: The non-electrical parts in this phase are plastic.

Magazine – Issue 14

  • Assembly Guide: Model Instructions
  • Track Legends: Lancia Aurelia, Bugatti Veyron, and Aston Martin DB5
  • The Story of Motorsports: Hockenheimring and The 750-Kilo Formula 1934-1937
  • Ace Racers: Juan Manuel Fangio
  • Challenging Circuits: The Isle of Man TT


The Control Circuit Board

Step 01

Retrieve your 300 SL Chassis assembly and carefully turn it over.

To protect the delicate rearview mirror and steering wheel while the Chassis is upside down I propped it up on a couple of tape rolls:

Fit the Control Circuit Board over the matching posts on the underside of the Floor Pan with the largest 4-pin plug towards the front of the car, and aligning the four screw holes as shown:

Secure the Control Circuit Board to the Floor Pan with four (4) MP screws:

Step 02

Guide the red/green wires of the Brake Pedal Switch and Wiring (part 38B from Phase 38) *AND* the red/black wires of the On-Off Switch and Wires (part 49A from Phase 49) along the left underside of the chassis and back to the Control Circuit Board. Fit the four Small Cable Clips over the wires at these locations and secure the clips to the Chassis with four (4) CM screws (one each).

This is your friendly reminder to try using 3-in-One Oil on all screws going into metal:

Fit the Large Cable Clip over the wires at this location on the Rear Left Half Shaft (fitting the clip’s pin into the matching hole), and secure the clip with one (1) OM screw.

This is the hole that the locating pin of the Large Cable Clip fits into:

Step 03

Connect the plug of the red/green wires of the Brake Pedal Switch and Wiring into the socket labelled ‘D’ on the Control Circuit Board.

These plugs are designed to only fit one way into the sockets. Do not force them in backwards:

Connect the plug of the red/black wires of the On-Off Switch and Wires into the socket labelled ‘E’ on the Control Circuit Board:


Sadly, after waiting many months to continue this build, we can only install this circuit board and connect some wiring. The other parts I have received are for later in the build. I do not know how long it will take to get to the next phases.

Next Up

Phase 52 – Body: Roof

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