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I am completing the build of a Sling TSi.  I have installed the engine per the Rotax manual and Sling's KAI.  I have also installed my avionics per the drawing and instructions of my panel builder.  All avionics work.  

However, I have no Lane Lights when I activate the B/U ECU power.  No fuel pumps in the same configuration with the fuel pumps switches on.  I effectively have nothing coming from the ECU.

I feel stupid asking this question because it will be assumed I must not have referenced the correct manuals and/or procedures.  However, I cannot locate ANY procedures anywhere that tell me how to get power to the fusebox and ECU.  I have looked in ALL of the Rotax installation, maintenance and heavy maintenance manuals.

I even went so far as to ask AI and received this answer...  "If the ECU and fuse box are truly powered, the lane A/B lights must come on when the lanes are energized, and at least one pump should run during the priming/start sequence. The fact that neither happens strongly points to no power into the Rotax box."

I keep coming across vague information that suggests I need a connection from the + of the 12V battery to the "battery‑power input stud for the fuse box".  I'm assuming that's on the Regulator B side of the fusebox and I see nothing except ground studs there.

My panel builder tells me to reference Rotax.  

What am I missing?

  • Re: No Lane Lights, No ECU

    by » one hour ago


    Hi Rob,

    The airframe power for starting the engine and running the fuel pumps comes from the start power switch or the backup power switch.  Both of these inputs are connected via X3 connector at the fusebox. The X3 connector only has 3 wire terminals.

    Terminal 1 = 12+ volt input to fusebox from the back up power switch.

    Terminal 2 = 12+ volt input to fusebox from the start power switch. 

    Terminal 3 = 12+ volt charging output from fusebox to the airframe power bus.

    You also need the B regulator ground plate grounded to the airframe ground buss.  The A regulator ground plate is isolated from the regulator B ground plate and these are only connected together when the start power or backup power switches are closed.  See attached diagram from section 92 of the 915 installation manual.  

    The start power switch and backup power switch do similar things, both provide airframe power to the fusebox but are intended for different purposes.  You could use either to start the engine but normal starting should be done with the start power switch, which should be the momentary type so the switch is not left on after the engine starts.  Once the engine is started airframe power is disconnected from the fusebox by releasing the start power switch and the engine systems are then electrically isolated from the airframe and running on alternator A. 



     

    44905_2_IMG_1812.jpeg (You do not have access to download this file.)

  • Re: No Lane Lights, No ECU

    by » one hour ago


    I believe I have seen this information before, and recall during the installation following similar steps.  I will check again tomorrow to ensure it is as you have indicated.  

    Thanks!


  • Re: No Lane Lights, No ECU

    by » one hour ago


    Rob,

    I made a couple edits to my last post to make it more clear…. I hope. 


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