Steamy Windows!

Hi, Hope someone can help, i have a '97 C70 T5 and having problems with the windscreen misting over. It seems to happen on damp days when the car has been used and left for a little while, i get back in the car and the screen will have misted over whilst it has been left; it then takes ages for it to clear with the blowers / aircon on full blast on the windscreen, i have driven to work (about 12 miles) with the blowers on full blast and it has still not completey cleared! The carpets are not damp and i can see no evidence of water ingress, although the blower on the screen does not seem very powerful compared to other cars i have owned. I have tried using 'Rainex' as well, but still have the problem, although not as bad. Anyone got any ideas?

your pollen filter could be due a change causing bad/restricted air flow. Is the mist greasy/smell of coolant? Is the car misted up before you put the fan on? If it is misty before you put the fan on it could be a blocked drain hole. it's the hole at the bottom of the picture, there's also one in front of the fuse box in the same place on the other side.

steamy windows 

heater core leak? 

Are you also slowly losing coolant? If your core is leaking into the cabin, even a small bit, it contributes to window fogging.

aye - the cause of steamy windows is the interior is damp. Need to find the cause of the damp - not try and find why it's not demisting efficiently. Driving with the heater on full and the windows open will help remove the damp. Air-con/dehumidifer alone won't do this on it's own. The only misting you should have is literally your breath when you get in on a cold morning.

Ref. Steamy Windows 

Hi, not sure if this helps, but my last car suffered greatly with steaming windows whenever it had been raining due to an element (slight) of damp getting into the car. It took me a lot of searching to find the cause but in the mean time, upon recommendation, I bought a bottle of anti-fog from Halfords. Yu just poor a small quantity onto a rag an rub over the inside of your windows, once done lasts ages. It will stop them misting over until you can locate the source of the problem. Kind wishes Wayne

I have found that most cars after the 900 series mist up easily inside, especially this time of year. I think they do not have the ram-effect through flow of air that the pre 850 cars had. The 855/V70 can be fitted with extractor fans in the cargo area to reduce this. Bob

I had the same problem on mine, changed the cabin filter and it's been fine since.