In article ,
Frank Erskine wrote:
On Sun, 2 Jan 2011 14:40:01 -0800 (PST), Andy Dingley
wrote:

On Jan 2, 9:02 pm, Roger Mills wrote:

As others have said, it's pretty certainly an earthing fault.

You can diagnose rear light cluster earthing faults quite easily -
look for a Ford or Renault badge. However they make them, they haven't
got reliable earths to the rear clusters.

It would probably be much better to use a wire "earth" return, rather
than rely on the chassis.

You've got a major problem if the 'chassis' doesn't provide a good ground.
Since that's the way it's done on every vehicle made of steel. Only glass
fibre ones need earth returns.

I dunno this vehicle, but the rear light ground may be clamped by a lamp
unit fixing screw. Which is a stupid way to do it. But faster for initial
assembly at the factory. Making a decent nut and bolt ground to a nearby
convenient part of the body is the way to go.

--
*Never underestimate the power of stupid people in large groups.

Dave Plowman London SW
To e-mail, change noise into sound.