I have a Transit 2.5 DI (1999) that proves difficult to start in the mornings when the temperature is around 0°C and nigh on impossible at -3°C or less. This model doesn't have glow plugs and I've changed the battery already. Once it's been started, it'll start easily all day long. There's a cold starting aid mentioned in the owners manual, but I don't know what that does, or if it can become faulty. Any ideas folks?