Well... after all that trouble I think I fixed my heated/cooled seat issue...
Today, I received my buzzer, and I wired it across the circuit breaker. Started the car up and fiddled around with the heated seat controls. The buzzer started buzzing... and kept buzzing and buzzing... I shut the car down and waited a minute and started it up again... still more buzzing. I ended up shutting the car down for a few minutes to let the circuit breaker cool off.
While the car was off, I started playing with the wiring under the drivers seat. I unplugged the large yellow connector and started the car. No buzzing. Of course the power seats didn't work, and the heated seats wouldn't work either. Got some warnings about the parking brake and airbag system. Shut the car down and reconnected the yellow connector.
Next I pulled off the narrow black connector (see picture below) and started the car. Same as before. No power seats, no heated seats. At least there was no warning about the brake or airbags this time. I shut the car off and reconnected the black connector.
Just to be sure I didn't mess anything up, I started the car one more time... This time I could feel cold air on my back! The vented seat had automatically turned on! I tried the passengers vented seat and I could hear the fan spin up! YAY!!! Next was the heated wheel and seats. I tried each and they all stayed on. No short, circuit breaker didn't trip. There was no buzzing!!!
It's been good for a few starts... I'm starting to feel confident that the issue is resolved. Don't ask me WHY it is resolved. Maybe the black connector wasn't seated properly???
Anyhow, I'm glad it's fixed and I'm grateful for all the help that was provided here! THANK YOU!
...and this is the connector that seemed to fix everything...
ARGH!!!!!! After making that last post I decided to be a smart guy and wiggle around in the seat. Sure enough the problem returned. Buzzzzzzzzzzzzzz... Seems to happen when I lean towards the center console.
I've tried to feel the wiring harness under the seat but I don't feel anything frayed or trapped. Looks like my next step is to pull the seat out and give it a good once over. That will need to happen when I have lots of spare time and don't need the car.
I'm sure that everyone is getting tired of my posts, but I'm much closer to fixing my issue. I found out where I think the short is happening. In the seat back, behind my left shoulder (circled area of the photo). When the vented seats seats are turned on, and I press in this area, the fans stop blowing until I stop pressing.
So... How hard is it to get the skin off of the seat back? More importantly, how hard is it to put back on?
Anyone ever have their seat apart? What can I expect to find in here? Anyone got a diagram?
If the seat has an active headrest and an internal (thorax) airbag, you might want to consider having a trained technician do it. I don't know if an independent upholstery shop would mess with it because of insurance liability? You can ask.
The seat has to come out of the car and set on a clean bench at a comfortable working height. The seat can then be carefully taken apart and put back together.
The actual seat covers are unzippered and then peeled then off the cushions, which is nice. Hog rings may be reused if undamaged. A proper hog ring tool helps.
The heater element may be serviced with the seat cover only, which is incredibly expensive if it is leather.