While it is too hot to work in the hangar, I’ve been playing with my panel install with the aim of identifying all the wires I need to buy and where to run them. It is a low rush job in this heat, but something I can do in the a/c. Helps of course that I have an enthusiastic and supportive wife that will let me bring the work home.
It took me a few weeks to source all the screws I needed to put the pieces into the panel (why something that costs 300-3000 can’t come with four 75c screws I do not know) but everything bar the throttle and choke cables are in and secured. For the first time I put the headphone jacks in.
There’s still one more thing to put and that is the music input, a 3.5mm jack, but I need to drill a hole for that and don’t have the drill here to do it.
With everything in the panel, I looked at all the wiring harnesses supplied by MGL and, very much like with a jigsaw puzzle, scratched my head for a while to work out the magic sequence of things.
There are two RS232 outputs on the back of the iEFIS. RS232 1 will take the power for the box and control the remote transponder unit
The plan is to put the transponder under the passenger seat but I’m not sure the harness will be long enough so it may go under the pilot seat. Even then it might be too short in which case I’ll need to evaluate my options for lengthening the cable. Anyway, apart from the supplied connector I need to get a couple of wires to hook up the Tx/Rx wires between the EFIS and the transponder.
The second RS 232 will be my “CAN bus” which is just a fancy term they have for being able to connect some items in series.
The first stop on the bus will be the RDAC (engine monitoring) unit which will be on the firewall. If I can find somewhere to put it, it will be on the engine side of the firewall but might end up pilot side. It has a power and ground that need to be connected. From there the bus will go to the SP-6 electric compass which I had planned to be under the pilot seat but that will depend on the transponder location.
It also needs connecting to power and ground. The bus comes to a grinding halt at the compass and will be terminated with a, er, terminator resistor.
That just leaves the massive wire bunch in the middle that is coming out from the radio. I’m still trying to wrap my head around where all the wires go but there are wires for the PTT switches on the stick grips, an Rx/Tx pair that will go back to the EFIS, plus power and ground wires.
There’s an audio input Hi which I think will hook up to the audio output wire from the EFIS (presumably for audio warnings such as “cockpit on fire” or “out of beer”). But there there are also Pilot Isolate and Dimmer control which I have no idea what to do with.
Anyway, I think from this I’ll be able to put together a shopping list for wires and connectors that will allow me to get cracking on the install. Not entirely sure how the power and ground cables will work, where they will attach to but plenty of time to work that out.
Update: The transponder can go anywhere, there is no cable that has two ends on it, just have to run power/ground wires from it to their respective places.