912iS Electric Problem

The power for the fuel pumps come from the Rotax fuse box.  HIC A is wired to the X1 connector on the fuse box and HIC B to the X2 connector.  The fuse box contains the fuses that protect the pumps.  Don’t ask me for a pin out for the X1 and X2, as I don’t have them.  Maybe one of the more Rotax savvy contributors has this information.

I too have a Van’s RV-12iS and was one of the initial owners that suffered from this issue.  For me it was the aux pump that would not run - pin #8 on the Van’s 8-pin HIC connector.  I am STILL waiting for the official SB to be issued - they sent me a preliminary copy not for distribution.  I have installed the harness support bracket, but Van’s says the connector harness has not been stocked yet.  How did you get yours?

As for your issue with the fuel pump switch LEDs not illuminating, do you have the 12iS wiring diagram?  If not, download it from Van’s web site at SUPPORT then DOWNLOADS.  I’ve attached a snippet from the wiring diagram showing the fuel pump switch connection diagram.  Note that if neither of the fuel pump switch LEDs are illuminating, the common connection is the power source, which comes from the Van’s Power Module (module with the fuses).

As a side note, after the aux fuel pump failed, I also lost both of the Lane start circuits, which also run through that 8-pin connector.  Could not start the aircraft, so it could be worse.

Barry,

Was this the first run of this aircraft or has the aircraft previously run successfully?

The Rotax 912iS Installation Manual has a thorough explanation of the electrical system, see chapter 24-00-00.  It’s a bit of a time investment, but worth it.  The grounding system is well explained starting on Page 6 of this chapter and there are some typical wiring diagrams that help clarify how the system works.  I found this information valuable for understanding and troubleshooting the electrical system. 

Hi Jeff, thanks for the info. This RV12 has 40 hrs. of flight time, but was inactive all summer. The owner made one flight when he came back, and all was good; the next flight he had the problems. I'll check out the install instructions. Cheers Barry

Hi Bob. thanks for the info. I called tech support and told them the aircraft was AOG and they sent a harness (ten days later) and the instructions to install it. I believe I spoke with Eric at Van's. Cheers Barry

Hi Barry and Bob,