912iS wiring

[efwd]

All right John, I’ll be honest, Im challenged here too so I bought my harnesses for that display to 912iS interface. What I have is two D sub plugs each wired with several wires. I refered to the 912iS manual and inserted the wires into the HIC pin out listed for each plug and HIC connector. Yes these are hooking up to a diagnostic tool, I believe referred to as a dongle. Dont quote me on that but I believe its right in the manual. Now, maybe Carl will fill you in on the gadget that I believe he has. Or Go onto Trent Palmers last you tube post on the firewall forward install. He explaines the device on there. Pretty cool. I was to intimidated by electrical I figured that thing was going to cause me a great deal more headache than its worth but Im certain to have a headache when faults start popping up. Maybe Ill invest then.

[jiott]

John, I also had many "not connected" wires in my Skyview/EMS system. I just left a reasonable length of wire in these places and coiled them up and zip tied them together and left them be. Its amazing after 5 years how many of them I ended up connecting to some new doo-dad I added later.

[efwd]

Ive got some of those also that I left there as Jim did.

[rosslr]

Yep, the two maintenance wires for from the HIC go to DSubs for downloading the files from Lane A and Lane B - I mounted the two D Subs on the panel and get my friendly LAME to download the files as needed for checking. The dongle from Rotax is about $1k so I cant justify that expense.

Cheers

r

[JMH]

It’s time for my next wiring question. When wiring the backup battery switch and the start power switch, the diagram shows a connection to the regulator board A for each switch. Are the connections just to the side of the regulator with all of the ground connections? So I’m grounding each switch twice? One to the regulator and one to the ground block? I’ve examined the regulator, and see no other connections.
Thanks
John

[efwd]

John, everyone here knows I am no electrician and someone will need to confirm this. It makes sense to ground twice since the second ground in the back up power half, will complete the circuit if the first ground failed.

[PaulSS]

Haha, no Eddie, doubling up for redundancy is not the way this setup works

One side of each double pole switch is power, the other is earth (ground). The 912iS has two types of earth; Airframe and Engine (EMS). When you throw either switch, on the earth side of the switch you are connecting the EMS earth (on the Regulator A plate) to Airframe earth.

I've attached a simplified version of my layout. You'll have to ignore the start timer, which takes the place of a start power switch. If you have a look at the Backup Battery switch you can see how the right side of the switch is the 'earth side' and how the top of the switch connects to EMS (Regulator A) and the bottom to Airframe.

I apologise if this wasn't the question you were asking and that I've got the wrong end of the stick.

Edited to add: yes, it looks like you were just asking for the physical location of the grounds. I've attached a diagram of the earth points for EMS grounds on Reg A. Sorry its so small but it's a restriction on the size of the photos we can attach.

[neville]

It all comes about because Alt A/Reg A provide power to the EMS/CPU/Fuel pumps as an isolated system not connected to a/c battery or to a/c ground. Start power must come from the battery system and that has to include a/c ground. Hence the start power switch to momentarily provide battery and a/c ground to the EMS/CPU system. In order to reduce the number of wires passing through the fire wall I ran one a/c ground wire to an insulated post mounted on the avionics tray near the CPU and then a/c ground wires to both the start power and to the back up battery switch from that post.. For 12volts to the switches I came off the main bus bar which of course is a source of 12 volt battery power already through the fire wall.