Icom-Flightcom interface insanity!

[74-07]

We're finalizing an upgrade to our second-owner RV-7. The new Skyview, which replaced an EKP IV, has been installed and is working perfectly. Financials dictate that, for now, we keep our original comm. radio and intercom. We'll add a Dynon comm. down the road. So, in short, the new install didn't touch the old comm. setup or wiring. After we were sure all was good with the Skyview, we slid the original Icom A200 back in the tray and reconnected the Flightcom 403 intercom. Neither worked!!!!! The Icom will transmit a carrier but that's all. No modulation. No reception at all. Also, the intercom is intermittent. Sometimes it works, sometimes it doesn't. Here's what we've found and done.

Aircraft has pilot and coplit jacks and PTT switches. Only other option is audio input jack.

Icom A200
1. Reseated radio in rack multiple times. It powers up, displays freq., TX lights up when mic switch pressed but not transmit or reception. Checked antennae connection in back of rack and radio seems to be seated. Wiggled ant. connector and no change.
2. We do not have an aircraft specific wiring diagram so, we're going to try putting together one utilizing the diagrams for each component (Icom and Flightcom) so that we can begin to go wire by wire to check for continuity, grounds, etc. but the success of this depends on this aircraft being wiring exactly like the factory shows.
3. We have checked the grounds and all appear normal
4. Radio installed in another aircraft and works flawlessly.

Flightcom 403
1. Has worked off and on. It was clear as a bell earlier today and then failed.
2. We did find one bad solder joint on co-pilots audio jack.
3. Looking at the wiring diagram and comparing it to the actual connector wiring, there are some wire to pin connections that are not according to the standard diagram but the airplane flew 350 hours before developing this problem.
4. Installed 403 in another plane and it worked perfectly.

So, after three days chasing wires, neither the radio or the intercom work. I do have an electrical pro helping me and he is as frustrated as I am.

Does anyone out in RV land happen to have this same setup and have a wiring diagram? We've decided that the only solution is a wire by wire wringout and without a diagram, it's going to be a long process.

Thanks

[rvbuilder2002]

The radio and intercom are capable of operating entirely independent of the Skyview system, so it is likely that during removal of the old panel equipment you removed or accidentally disconnected something.

The other possibility is that while trying to connect output audio from the Skyview to the intercom/radio system, something was done incorrectly.

Does the intercom still function normally between the two headsets?

Are you able to hear audio from the Skyview system in the head sets (if you put Skyview in to audio set-up mode it puts out a constant test transmission)?

[74-07]

There was no audio connection to skyview. We have looked at all of the wiring multiple times and we cannot find any loose wires or connections.

No, at the present time, the intercom between headsets does not work. It did earlier today and was perfectly clear.

Arghhhhhh!

[DennisRhodes]

The A200 has an internal intercom i believe. Be sure that the internal intercom is not turned on and causing the conflict with the 403.

[74-07]

We'll check that for sure!

[RV3bpilot]

I had to send my New radio back to the manufacturer for a new power supply circuit board because the original ones were junk and would make all kinds of noise. Now my radio is nice and quiet.
Oh my radio is a Val Com 2000.
Of course I checked everything else out to make sure it was the radio, that took time and patience. Sending the radio in for repair was my last option.

[74-07]

Finally located the problem today. Intermittant ground to headset jack! In the process, a good friend that is an automotive electronics expert, created a beautiful airplane wiring diagram which includes photos of connectors and their pin connections!

Life is good!