A short or something else

There are a few of possibilities:

1. The Dynon is misreading. If you have a multimeter capable of measuring 20A, you could connect it in series with the current shunt and just verify that the Dynon is reading correctly. Alternatively if you have access to a DC current clamp that would be easier to use.

2. A fault on the main feed from the generator to the main bus bar (that supplies the breakers). I would look at this once you have eliminated the other sources of the problem first.

3. That there is a fault in one of the electrical load circuits.

Assuming that the problem lies with one of your fused loads, I would switch off all of the loads except those needed to run the engine and the Dynon. Just pull out the breakers to isolate the circuits. Run the engine and make sure that the current is stable and low. One by one, switch on each of the loads in turn until you find the ciruit that it causing the problem. You can then investigate the wiring and the load.

Once you have narrowed it down you should be able to fix it.

I took the plane for a test flight after charging the battery to see what would happen.  When I left the battery had 13.02 volts.  I flew for .7 with all electrical components turned on and everything stayed in the green.  However, when I would press the comm button on either stick it would discharge the amps to a level that was not good.  When I landed the battery voltage was 12.74.  It seems that something is constantly pulling energy from the battery and that the comms may be the culprit.  Now I just have to use your helpful advice and see if I can figure out what is doing it.

So are you saying that when you press the radio push-to-talk button the current goes up? Do others receive your radio transmissions? I would have thought that if you had a problem with the radio that was drawing an additional 7A then it would trip the breaker. What current rating is your radio breaker?

It seems to only draw a large amount of current when the comm buttons are pressed.  It does not affect transmitting or receiving any radio calls.  Since this was purchased as an S-LSA, I have never looked into the current rating of the radio breaker.  What is the best way to do that?

I thought that the current rating was written on the end of the breaker reset button. I don't understand how your radio is operational when the circuit is drawing so much current. If I was fault finding it I would be measuring the current on each of the conductors connected to the radio. You need to determine if the problem is with the radio or the wiring. Do you have a circuit diagram of the aircraft's wiring?