I will have to give it a try. Indeed it seems to occur when the van is moving at high speed. It totally comes and goes. I will try and lubricate it as well. I made a recording of it via my iphone. I have to upload it so you can hear it.

Thanks!

Rob

On Feb 20, 2011, at 11:08 AM, Alistair Bell wrote:

> does it only occur when van moving? if so it might be speedo cable as
> you guessed. if so, try lubing... disconnect cable from speedo head
> (either a pinch clip affair or screw on, depending on van year, should
> be obvious), some light oil in the cable.
>
> alistair
>
>
>
>
>
>
> On 20-Feb-11, at 12:52 AM, Robert Stewart wrote:
>
>> Rob,
>>
>> Thanks the reply. This most definitely comes and goes. It sounds
>> like it's a weak electrical short but with a strange frequency I
>> have never heard before. Definitely not the any pressure/coolant
>> etc. alarm sound.
>>
>> Which relay is the Turn signal unit? How might I test to see if a
>> relay has gone bad?
>>
>> The weird sound seems to be coming out of the speedometer to me or
>> the lights above the speedometer/odometer. Could they be burning out?
>>
>> Could it be the speedometer cable whining at high speed and just
>> making a noise? Could I somehow spray lubricant where it connects to
>> the module in the dash to solve it?
>>
>> Thanks,
>> Rob