For as long as I can remember since buying the car, once I would hit about 70 mph and having the radio volume above 20, the speaker tends to hiccup every 15 seconds or so. This issue's odd, as if I lower the volume below 20, the issue doesn't happen, or at least I haven't experienced it. The car is a 2005 S-Type R, and the speakers all around the car have this hiccup, not just one of them. Any advice or thoughts on what the issue could be? Automatic Volume Control is turned off, I'm thinking it may be a loose wire or something. I've tested using CDs and different radio stations. Thanks for any advice.

 

This sounds like the beginning of a clock spring problem. Are the audio controls on the steering wheel flaky on turns? And the clincher....any problems with the cruise control?

Steering wheel volume control operating in reverse was first indication of failing clock spring. 30 days later, cruise control went. Problems were progressive. (Note, my response is based on a 1st generation S-Type. Yours has a newer fiber-optic bus, as opposed to the older wire harnesses in my 02).

Finally, any "Axxxx" codes, that won't throw a check engine light?