Vans Aircraft RV-12 Airplane Build, Section 45A: Firewall Forward Wiring Harness (part 4)

Reference for this entry: pages 45A-05, 45A-06, 45-07, 45A-08; 3.0 hours

Today I got a lot done on the RV-12 airplane's wiring. And ran into a simple but frustrating "Gotcha." Simply put there is a gromment that need the be modified by cutting a 5/8" hole in it. The directions say "cut the hole with a 5/8" OD socket." What it means is cut it with a socket that has an outside diameter of 5/8" NOT A 5/8" SOCKET!

Step 1: Modify the grommet by shearing it in a vise with a socket having a 5/8" O.D.



Step 2: Insert the grommet into the large hole in the fuel pressure sensor bracket. Then mount the bracket on the firewall.



Step 3 was performed after I got a new grommet from Van's Aircraft. Reference: page 45A-06

Step 6: Separate and strip the ends of both red and both yellow wires coming from the brwon Exhaust Gas Temp Wiring. Crimp male spade connectors on each of the four wires.



Step 7: Cut the existing spade terminals off of the EGT Sensors, leaving as much wire as possibly. Strip the end of the wires and install new female spade terminals.



This completes page 45A-06.

Reference: 45A-07

Step 1: Separate the three wires that go to the Manifold pressure sensor.

Step 2: Insert the wires as directed in the RV-12 plans by Van's Aircraft into the Weatherpak connector.



Step 3: Install the Weatherpak connector into the Manifold Pressure Sensor.



This completes page 45A-07.

Reference page 45A:08

Step 1: Remove the outer nuts and washers from the terminals on the Master Relay. But do not remove the nut laying against the relays case.



Step 2: Slip the ring terminal ,closet to the red band, of the ES Diode Master through the insulted boot and onto the right stud of the Master relay. Also slip the free end of the Battery Power wire through the same boot. Then tighten it to the relay.



Step 3: Separate the White and Orange Master Relay wire from the wiring harness. Strip the end and install a ring terminal as directed in the RV-12 airplane plans.



Step 4: Slip the unconnected ring terminal from the ES Diode Master and the Master relay wire through a insolation boot and onto the front stud of the Master Relay.



Step 5: Slip a insulated boot over the end of the WH-P154 Starter to Master Relay Cable. Connect the terminal to the left stud on the Master Relay.



Step 6: Remove the nuts and washers for the two studs on the Starter Relay.



Step 7: Find the and route the WH-P157 Battery Power Wire through the cushioned clamp on the engine mount. Strip the end and install a ring terminal.



Step 8: Slip the ring terminal through a insulated boot and onto the left stud of the Starter Relay. Terminal is pictured below but is not in focus.



Step 9: Slip one end of the WH-P155 Starter Power Cable through a insulated boot and onto the right stud of the Starter Relay. Tighten the terminals down on the studs.



Step 10: Separate the spade connector crimped onto ORN and PRP wires from the engine harness. Insert the female spade connector onto the male terminal located on the lower center of the Starter Relay.



Step 11: Remove the right side mounting bolt from the Starter Relay and slip the ring terminal attached to the wire covered with Blue heat-shrink coming from the engine harness. Reinstall the bolt and washer.



This completes this entry and today's work on the RV-12 airplane's engine wiring.

Vans Aircraft RV-12 Airplane Build, Section 45A: Firewall Forward Wiring Harness (part 3)

Reference for this entry: pages 45A-04, 45A-05, 45A-06; 1.0 hours

This is the next installment of the RV-12 airplane's firewall forward wiring.

Step 1: NA Top Skin was previously removed.

Step 2: Install the WH-00063 Rotax Fwall Fwd Harness 25-pin connector labeled "FWL FWD" to the Control Module.



Route the Fwall Fwd harness through the cushioned clamp near the CPU Fan on the base plate and through the firewall penetration.



Step 3: Install the Power Wiring harness to the back of the Power & Switch Module and route the wires through a snap bushing in the Com Support and out through the firewall penetration.

Builder's note: The two supplied snap bushings are crammed full of wires with no more room. So I added a new snap bushing in the Com support and ran the wiring through it.





Step 4: Install the Exhaust Gas Temp Harness. to the engine Monitoring Module. Running the wires through the cushioned clamp near the CPU fan and through the firewall penetration grommet.



Steps 5: NA See Step 6.

Step 6: The tube I used is long enough to span the complete distance so no splice was needed. The whole story is I melted the original tube through on a lamp when installing it in the tailcone and had to replace it. So I routed the new one through the firewall penetration.



This completes page 45A-04

Reference: page 45A-05.

Step 2: Deburred the fuel pressure sensor bracket, prepped and painted it.

Reference: page 45A-06

Step 1: Route the Wiring through a cushioned clamp attaching it to the Engine mount.



Step 2: From the Power Wiring Harness separate the W-P156 wire that splits into two wires three inches from the end. Attach a spade connector supplied with the regulator connector. Then insert them into the correct locations ensuring they are locked in place.



Steps 3 & 4: Separate the Wh-P761(YEL) wire from the wiring harness. Attach a supplied spade connector and insert in the position indicated in the RV-12 airplane plans.



Step 5: Insert the connector into the Rectifier Regulator.



This competes today's work on the RV-12 airplane. Tomorrow I will pick up where I left off.

Vans Aircraft RV-12 Airplane Build, Section 45A: Firewall Forward Wiring Harness (part 2)

Reference for this entry: pages 45A-02, 45A-03; 1.5 hours

I had a hard time finding some of the part for today's work on the RV-12 airplane, namely the rectifier regulator and starter relay. These are in a box that are shipped in the engine crate. I'm not used to engines coming with the accessories. In fact, the Rotax even comes with oil!

Step 4: Secure the Odyssey Battery. Builder's note: The was done later after the paint on the hold down dried.

Step 5: Install the Master Relay, Starter Relay, Manifold Pressure Sensor and Rectifier Regulator to the Firewall.



Builder's note: On the Manifold Pressure Sensor I had to use thin washers so as to have enough threads showing for the nutplates.





Reference: page 45A-03

NOTE: DO NOT CONNECT the Battery Ground Cble to the battery at this time!

Step1: Install an insulated boot onve the end of the WH-P150 Battery Power Cable with the smaller ring terminal. Attach the Cable to the positive side of the battery in the RV-12.



Step 2: Using the hardware called out by Van's Aircraft attach the Battery ground cable to the Oil Reservoir Brace with the Engine Ground Cable.



Step 3: Install a Insulated Boot over the unconnected end of the Battry Power Cable and tape ti in place to isolate it from possibly touching the airframe.

This completes page 45A-03 and today's work on the RV-12 airplane.

Vans Aircraft RV-12 Airplane Build, Miscellaneous

Reference for this entry: pages 29A-10, 34-11, 40-11; 3.0 hours

Today the plan is to to do a mixer of different tasks on the RV-12 airplane and there by start pulling some of the odd jobs together.

Reference: page 29A-10

Step 4: Install the screws that anchor the back of the Map Box to the Base Panel.



This completes page 29A-10 of the RV-12 plans.

Reference: 34-11

Step 2: Rivet the latch block to the Canopy Lock.



Reinstalled the Canopy guide blocks that had been remove form painting.



Reference: page 40-11

Builder's Note: Because the wiring had already been ran from the instrument panel back to the RollBar the steps on this page will be out of sequence fro the RV-12 plans.

Step 1: Drill #12 hole for lighting wires into roll bar.



Step 2: Insert a snap bushing in the hole, but first trim the sides of the bushing so it will set between the front and back frames of the roll bar.



Step 3: Remove the two lower right rivets.


Step 4: Machine countersink the three holes int the light bracket that attach the Cockpit light.



Step 5: Cleco the Light Bracket to the holes from the rivets just removed.



Step 6: Match-drill #30 the right two holes in the Light Bracket into the web of the Roll Bar.



Step 7: Rivet the light Bracket to the roll bar.



Step 8: Crimp on butt splices to the two wire coming out of the Cockpit light.



Step 9: The lighting wire have been run previously. But needed to be ran throug the roll bar. I used a length of light safety wire to pull the wires up through the roll bar.





Step 14: Enlarge the guide hole in the Roll bar attach Plate to 3/8".



Step 15: Inert a snap bushing into the hole after deburring the hole.



Step 16: Make a Wire tube out of PT-035X1/4 tubing 30 inches long.



Step 17: Used the safety wire to pull the wires up through the wiring tube and out through the hole in the Roll Bar.





Step 10: Crimp the butt splices onto the appropriate wires.



Step 11: Rivet the Cockpit light onto the Bracket using the called out rivets.

Secured the wires to the Roll Bar using a drop of fuel tank sealant.



This completes page 40-11 of the RV-12 airplanes plans and this entry