QuestionThe sound turns from normal to a 'hiss' frequently. (Radio, CD, XM) It seems to be heat related. The warmer the outside temp the more likely it is not to work. Pounding on the dash board used to fix it. The speakers would 'pop' then work. The problem is getting worse. any ideas? Thanks!
AnswerThese intermittent conditions are difficult to locate.
This one sounds like a loose antenna connection of something in the front end.
You must find out if it is internal to the head unit or external - such as wiring or antenna connection problems. Since it does the same thing on CD that eliminates the antenna as a problem....
You could pull the head unit and bench test it if you are brave; it requires pulling it out of the dash and hooking it up to a battery and separate amp/speakers.
But, based on the fact it exhibits the condition on all input sources I think you have a bad connection or cold solder joint internally.
With the age of the car; is the HK unit same age? It may be ready for a replacement. Otherwise, you may have to bite the bullet and have a tech dig into it an find out where the culprit is hiding.
Hope this helps.
Cleggsan
