Hi,

I am having trouble with the radio in my 300 TDI. When I flash the headlights the radio cuts out and then switches back on agian. Sometimes it does it when I indicate or switch the heater on. Or sometimes it just happens randomley at any time. I am asumnig it is a bad connection or a dodgy wire but I am wondering how best to tackle the problem?. It seems to be getting worse and is happening more reguarly. Your help and advice would be much appreciated.

Many thanks.

This happened to my 300tdi. It was bad earthing. I added a separate earth to the radio and it was fine. The previously installed spot lights and radio were earthed in the same spot and the initial surge of the spots was enough to upset the radio.

Hi Bobs,
How did you go about earthing it?

Thanks.

Kris.

I probably went a bit over the top. As I had a few suspect earths I ran another large diameter cable from the battery to the engine and chassis and then to a point on the bulkhead to which I have attached the radio and any components with questionable earths. The biggest culprit seemed to be a bracket behind the dash for the steering column which had a few earth cables attached so this was also attached to my new earthing point. But really all you need to do is connect a new/duplicate earth cable to your radio earth as well as the radio body and find a good earthing point to attach to. To test if it is the earth, run a temporary cable from the battery earth to the radio and try your lights then.

As well as the earth this could qite easily be caused by a lack of power as well on the positive side. Dest thing to do is to pull the radio out, and check how its being earthed onto te body, but i suspect if its the earth i could well be the earth strap between the engine and the body (the negative cable from the battery goes to the engine and then the body connects to the engine via a carge earth strap underneath).

With the radio out check the volatge between the supply cable (both switched and unswitched cables) and the negative terminal on the battery. If this is reading a good 12.5+ then flash the main beam and see if the voltage goes down. If this does not change significantly then its going to be an earth fault.

Check you earth strap to start with, and where the earth cable from the radio attaches to the bulkhead.

James