Wiring Of Starter & Master Solenoids, Battery, Starter - Completed

When continuing with the firewall forward wiring this work session, hit a bump in the road almost immediately. Van’s plans call for crimping an ES324082 crimp ring terminal with a 1/4" hole onto the P-157 wire which is a 12 AWG wire that feeds battery power to the AV-50001 Switch and Fuse module. Looking closely at the ES324082 ring crimp terminal revealed it is actually a terminal for #8 wire and won’t fit into my ratcheting crimping tool so it would require using the hand crimping tool. Because the P-157 wire is the main battery power buss to the AV-50001 Switch and Fuse module, felt it was wrong to knowingly crimp a connector designed for #8 wire onto a #12 wire ... so headed out and picked up a replacement ring terminal with a 1/4" hole designed for #12 wire.

One can see the hole in the yellow #12 ring terminal will fit the white #12 AWG wire much better and should make for a much tighter crimp on the wire  as opposed to hand crimping the red ES324082 #8 ring terminal onto the wire.


Once the P-157 wire had a ring terminal attached, it was placed onto the terminal on the starter solenoid closest to the left side of the airplane along with a #8 wire coming down from the master solenoid. The remaining terminal on the starter solenoid closest to the right side of the aircraft is for P-155 a #8  wire that supplies power to the starter motor. The P-157 wire is plenty long enough that should it be necessary to change to the other connector for some obscure reason, it can easily be done.


The custom ground cables Stein Air made for the DOG Aviation RV-12 came in a couple of days ago, so decided while working in the vicinity, now would be a good time to install them.

The Van’s original P-149 battery and P-151starter cables with the red terminals will be replaced by longer custom cables that Stein Air fabricated with white heat shrink covering the crimps. The longer cables will reach the grounding block modification on the firewall.


The longer custom P-149 battery ground and P-151 starter ground cables were installed onto the ground stud on the firewall (a grounding modification made to the DOG Aviation RV-12). The P-155 starter power cable was attached to the stud on the starter solenoid on the right side of the aircraft and connected to the starter. The nuts on the 992-819 starter relay and starter power wire at the starter were torqued to the specs given in the Rotax Illustrated Parts Manual of 35 inch pounds.

Completed wiring of ES-24115 master relay and 992-819 starter relay which is below the starter relay and mostly hidden by the white rubber boots covering the terminals. Also of note, the protection diode covered in blue heat shrink is normally installed on the other mounting bolt for the starter relay … because the engine is installed, this bolt was far easier to use as the ground point for the diode.

The new longer ground cables (P-149 battery and P151 starter) are now connected onto the firewall ground point … a modification installed on the DOG Aviation RV-12. For safety, the ground lead is not connected at the battery and the negative terminal has been taped over. Still need to use a couple of wire ties to secure the cables.


Have to admit, all this took far longer than it should have … had most of the wiring been done prior to mounting the engine, as suggested in the plans. But when wiring of the solenoids had just begun, the owner of the borrowed engine hoist needed it back so the wiring was placed on the back burner and the engine was mounted. Everything is still accessible … just more challenging.