Headset volume differs between sides?

[ErichKeane]

Hi all-
We were playing with our intercom today, and realized that the volume between the passenger side and pilot side is significantly different (even swapping headsets!) but cannot figure out what to do!

The pilot side is very quiet, whereas the passenger side is fine. Anyone have any ideas? I think it was ok in the past, so I don't know what we could have done in the meantime to screw it up.

 

[Mich48041]

Bad connection?

There could be a bad electrical connection at the headphone jack. Maybe some paint got in there. You could wrap a wooden dowel with very fine sandpaper and try polishing the contacts. Another thing to try is to swap the pilot and co-pilot headphone wires at the intercom. If there is no change, then the problem is in the wiring or jacks. If the problem moves to the opposite side of the plane, then the problem is inside of the intercom. The headphone wires are WHITE (9 & 11) and WHITE/BLUE (10 & 12). The pilot headphone wires connect to intercom terminals 9 & 10. The co-pilot headphone wires connect to intercom terminals 11 & 12.
Does the pilot headphone only have low volume while listening to the co-pilot or does the pilot headphone always have low volume regardless of the audio source, i.e., radio or GPS? If the only problem is hearing the co-pilot, then the problem could be in the co-pilots microphone circuit.
Do some more experimenting and let us know what you find.
Joe
You can view a partial schematic here:
https://lh4.googleusercontent.com/_9Rmupq9lpCs/TWmpHNOeg9I/AAAAAAAAAJ0/60AvWe9o5s0/Headphone.jpg

 

[ErichKeane]

It seems to be for everything. We couldn't get much radio signal in the hangar, but the pilot couldn't hear his own voice very well either.

 

[ErichKeane]

I figured it out! We ended up having the isolator washers on the ear portion rather than on the microphone jacks. I swapped these over, and it started working perfectly.

 

[Mich48041]

Good going

ErichKeane,
Good job troubleshooting.
Joe