Sound System playing sporadically.
 

Hi Friends, I bought a 2001 C180 Sports Coupe, a very beautiful car, but I had to replace the battery three weeks ago and since then the sound system has been doing strange things,losing the dial light and playing sporadically and at times not playing at all. What I can tell you is that when changing the battery, auxiliary power was used plugged into the cigarette lighter. How can I correct the problem.
Kind regards
Trevor
Barbados
West Indies