Work Begins On Firewall Forward Electrical

Not being able to get to the metal shop to bend the parts being fabricated until Monday, decided to try to make some forward progress and begin working on the firewall forward electrical.

Yesterday, after taking some measurements and playing around with some thoughts for future modifications, thought it would be a good idea to make a little forward progress on the RV-12 assembly and begin attaching some of the electrical components onto the firewall. The ES24115 master relay was mounted along with the 992 819 starter relay and manifold pressure sensor.

Mounting the ES24115 master relay onto the firewall.

From top to bottom … the Dynon 100434-000 manifold pressure sensor, ES24115 master relay and Rotax 992-819 starter relay.

The firewall forward wiring harness (WH-00063) needed to be fished forward from the instrument panel area through the rubber grommet in the firewall. Some wires on the firewall forward wiring harness are already terminated and others will need to be stripped and have the appropriate terminations added.

Fishing the WH-00063 firewall forward wiring harness through the grommet in the firewall.

The wires going to the ES24115 master relay utilize a rubber boot on each of the three terminals which led to an interesting complication when installing the protection diode onto the master relay.

The WH-P150 positive lead from the battery and the protection diode (hidden by the boot) yellow lead with the red stripe go onto the BAT terminal of the master relay. One can see there is virtually not much room left and the small ring terminal from the diode needs to go through yet another smaller rubber boot then attach onto the center post of the master relay along with another wire.

The leads on the protection diode are rather short and the rubber boots are rather long so it was somewhat of a fight to get the diode attached onto the small center post of the relay along with the WH-P759 white/orange wire that goes forward to the instrument panel. This task would not be fun if the engine were installed.

Wiring on the ES24115 master relay completed. One can see the larger rubber boot is being stretched by the diode’s lead. May just put a small slice in the boot to give the diode lead some relief.

By this time it was raining and the forecast was for freezing rains, so decided to pack it in for the evening before the roads became a skating rink.