Hi - this is probably a common problem, but would like advice please. I have a 2008 Micra Visia. recently the heater stops blowing warm air into the cabin, once the engine has warmed up. In addition, the red temperature warning light comes on and off. The temperature indicator light. I had a chat with a mechanic who said that the problem was coolant related. I tried topping up the coolant and this has had a small but positive effect on the frequency of the red warning light but no effect on fan temperature, which is still cold. The coolant compartment now seems fullish. I think that hte two are part of the same problem. I wonder what could be the matter and am seeking some advice, please?