In your reply to Brian Griffiths, reference the Renault Clio climate control problem, you said that any sticking relay should turn off when the relay is turned off. But if the points of the relay are actually stuck together, (which might have been one of the explanations. Doc) then the current will continue to flow through the points, even if you switch off the current to the solenoid itself. A good way to stop the flow of current through a stuck relay is to remove the relay from the fuse board, and thus from its connection to the battery. Then the substitution of the relay by one that you know works will help with the diagnosis of the problem. On many cars the relays are the same, so you can swap them about. New relays tend to be very cheap anyway. Surely if Renault can’t solve this problem on a new car then Brian should be entitled to another new car? As you say, any competent auto electrician would solve this. This shows that the main dealers no longer employ a proper electrician or are prepared to bring one in on a freelance basis.
Peter Duffy

Good point Peter, and good general advice for aspiring DIY auto electricians, for which I thank you. As you say, many main dealers don’t employ real auto-electricians these days – although conventional diagnostics of course don’t always work, what with Can Bus and all that… In many situations, you’re not looking for power or no power, but whether there’s any signal, and is it the right signal? There was a solution to the Clio problem, as we now know, and it wasn’t really a fault, but a crazy set-up, where they effectively intended the air conditioning to be permanently in operation. Hardly a justification for a replacement car, I feel though. It’s a bit like the car (no names, no pack drill) that I’m driving just now – I simply can’t find any way to stop the radio turning on every time the engine starts up. I can minimise the volume, or mute it, but unless I turn off everything else – satellite navigation etc., off, then the radio always seems to start up at an audible volume setting. Aaaaaargh.
Best regards,
Doc