Posted: Mon Mar 19, 2007 5:54 pm
Radio does earth through the aerial so that may be part of the problem. Not all Bongos have rear speakers - there have been various threads re fitting them.
Althought the radio will earth through the aerial, the radio itself should have its own earth ( the thick black wire on the mutiplug connector if memory serves but try the fact sheet on Bongo car audio) I would recommend that you put an extra earth to the radio - Quite simple really a piece of cable with a ring crimp on one end fastened to the main earth stud on the radio and connected via one of those electrical pipe-earthing connectors normally found on your domestic water pipes but in this case wrapped around the large round cross member adjacent to the radio- or any other convenient earthing point. For interference though first see if there is an aerial trimmer adjustment on your radio or you may need to add a couple of suppressors to your alternator and ignition coil ( petrol Bongo only) first thing first though ensure all existing connections are good ones.
Best of luck!!