Hi got a motorhome on Ducato chassis, and a Sony radio , the radio goes all bad when ignition key is turned on , but it’s brilliant when ignition is off , any ideas guys

More details required please=
what does 'goes bad' mean? Make/model of MoHo and electrical system and controller etc. will help.

interference when ignition turned on ,its an auto trail apache 634 L its supplied from the engine battery

Hi,, do you mean igntion on but engine not running? If so, sounds like some electrical/electronic device fitted is causing the interference. Is it possible yo can put an independent temporary supply instead to the radio, and switch ignition on again and see if it does it again? If it does, likely culprit is the radio. I can't think of any electric device that runs with ignition on, as I don't think it even has an electrical fuel pump? Does it have a split charge relay for a leisure battery-the kind perhaps that just connects across the battery terminlas and outputs charge to another battery when alternator volts rises above a certain level? I had one on a Renault, it made a quiet high pitched buzzing/whining all the time ignition on or not, but did not know if the radio got interfered with as I changed it as soon as I found out. Might be worth a look?

I had this fault once on a (petrol engined) car but that was so long ago I can't remember the cure; probably the points or HT leads not suppressed.

I guess as a start you could check that the sheathing in the co-ax cable connecting aerial and radio is in fact earthed (probably easiest to do this at radio end)

I have tried one of them aerials you stick on windscreen , that made no difference , I’m sure it’s ignition related , you can hear the Chang when you turn to first position (dash lights on, engine not running) when you turn off again it’s brilliant

Hi
you really need to be more specific on the fault
Whats it like with engine running?
LUIGI

Hi
its sorted itself out now im sure it was a dodgy cigar lighter usb plug , thought id pass on this if anyone else has similar problems

That would make sense as the accessory socket is ignition switched.

Hi there, I had similar problem, thought it might be the grounding of the radio and tried improving that. Everything perfect now.