PROJECT 7: Wiring the Electrical Components

In this project, you will install the secondary power switch, the power LEDs (light emitting diodes) and plug the PWM leads into the receiver.

Caution: Make sure to have adequate ventilation in the work area when using the liquid electrical tape.

Part 4: Installing the LEDs and Switch in the Bracket

Now you can take the power LEDs that you wired and install them in the switch bracket, along with the secondary power switch. You will prepare the connections for the secondary power switch and finish by insulating all the terminals and installing the bracket.

click on an image to enlarge it

Insert the secondary power switch with the screw heads facing outwards. Apply Loctite and tighten down the nut on the top with an adjustable wrench. Do not apply Loctite to the screw terminals. They will need an unobstructed path to conduct current.

Remove the servo connector from the red and black leads of the green secondary switch LED by using a hobby knife to lift the plastic that holds the pins in place, as you did with the white lead before. Pay attention where the leads go, since you will be putting them back in as soon as the LED is mounted.

Insert the wires in the LED hole closest to the secondary power switch, and pull the LED all the way down to the bracket. Thread the lock washer and nut onto the wires as shown and apply Loctite before tightening the nut on the mounting thread. Replace the servo connector on the end of the red and black servo leads.

Insert the leads of the red main power LED into the LED hole furthest from the secondary power switch. You may have to do a little bit of shuffling the lead around so that you have enough clearance to get the large 1/2 Watt resistor through the hole, lock washer and nut. Apply Loctite and tighten the nut on the mounting thread.

For the secondary power switch, you'll use a 12" Futaba J-type servo extension, which will be just long enough to make it all the way to the siwtch and back. Fold the servo extension in half and mark it in the middle. Using a hobby knife, separate the red wire from the blank and white wires in a 3" long area centered on the mark, dragging the tip away from your hand. Carefully cut the red wire only at the mark. Leave the white and black leads intact.


As with the speed control fans in Project 6, strip off twice the amount of insulation you normally would and fold it back to double the diameter. Crimp a 22-18 GA #8-stud ring terminal onto each side of the red lead. Screw the ring terminals onto the switch and tighten them down. You may want to bend the ring terminal farthest from the receiver over as shown so you get a little extra slack on the line towards the receiver.


Paint all exposed electrical connections with liquid electrical tape. When the liquid electrical tape is dry, you can install the switch bracket on the base using two 1/4"-20 x 3/8" long button-head cap screws. The open end of the "U" shape should be facing the motor, away from the battery. Since access to the screws is limited by the speed control, you should use ball end Allen wrenches to give you a greater working angle.

Route the secondary power LED servo connector and secondary power switch leads towards the receiver. The main power LED should be routed towards the closest speed control, near the position for the master power switch, where it will be connected in Project 8. [Note: This picture shows the main power switch, which has not been installed yet.]

Apply cable ties as strain relief to make sure that the fragile LED wires don't get pulled when you change receiver batteries or work on the receiver.