I recently had a Kenwood KDC-X798 radio installed into my car.
The AM reception was terrible. I went back to the business that sold the radio and installed it. I had them pull the radio out again to check the antenna connection. I could see that everything was connected. The installer and other workers at the business claimed the problem was the antenna on the rear window.
I wrote to Kenwood hoping to gain some insight. The best Kenwood could tell me was to check the antenna connection.
Lacking any information from the professional installer or the manufacturer, I began to do my own research on and off over a couple weeks, combined with a group consultation with a few very savvy ham radio friends.
The bottom line from my own research: my vehicle has a hidden antenna amplifier that needs power. Power was supposed to be injected into pin 14 of the vehicle’s radio connector. The Kenwood radio’s solid blue wire labeled “Ant Cont” (antenna connection) that was connected to pin 14 was not, after putting a volt meter to it, not putting out any power.
The manual for the radio showed the solid blue wire marked Ant Cont — but there was a little note in small print saying “not used.” (Why is it marked “Ant Cont” then?)
More research suggested that the unused PCont (power connection), a blue and white wire, might be the correct wire to connect to pin 14. So, I pulled the radio out, removed the solid blue and applied the blue-white wire. Apparently, that is all that was needed, because the AM radio came to life with good reception and the FM radio (with HD digital) also worked better.
Would it be too much for Kenwood to accurately label the solid blue wire “unused” — to match the manual — rather than “Ant Cont”? This would give the installer a heads up and reduce the number of dissatisfied Kenwood customers. And apparently, the professional installer was unaware that there was a hidden amplifier in the car that required power.