'99 v70R AWD foggy windows

I would strongly suspect a leaking heater core, what's the smell smell like?

It is the heater core that is causing your problem it is not a 12 hour job the dashboard does not get removed @ most 3 hours Glenn

It's hard to describe. Waxy. Not what I think of colant smelling like. Sounds like I should investigate the heater core though... I read it was a massive job somewhere and that the whole dash had to be dissambled. Glad to hear it's only a 3hr job.

-K

It really depends on the car, in some it truly is a massive job, in others it's not so bad. It's never easy though.

The fog pretty much gives it away, remember also that the coolant may mix with other stuff when it leaks which can make it smell different.

When the air outside is cold, DON'T use recirculate. Even cold foggy outside air is dryer than the warm inside air and letting outside air come in will eliminate the fogging problem.

When the outside air is not cold, you must use the AC when the defrost is on. This is normal. The AC will dehumidify the air.

This can be caused by shutting the car off with the AC on. Volvo's solution on newer models is to have the AC/heater fan kick on after the water has drained out of the AC housing. They do have sprays they can use to eliminate the smell. They are anti-fungal sprays.

This is also a problem. You usually get water on the passenger floor mat and sometimes the passengers legs when the drain is plugged. Usually the dealer can put it on a lift and clear it in a couple seconds. I haven't figured out where it is.

But he said only the vent on the right side is fogging the windows, I suppose there could be another explanation but it sure sounds like a heater core to me.

It sounds like a loose duct hose to me. The heater core leak should affect the entire cabin.

It's not that there isn't airflow, just that the airflow is obviously very humid on the right side. It's probably is a leaky core. I was worried about the misinformation I'd picked up that it was a 12hr job otherwise I'd have already opened it up.

-K

Heater core for sure - just had my new-to-me '99 XC done.

Luckily I found this when my shop told me the whole dash had to be taken apart:

Mine was worse on one side too, but definitely was the core - I think it's the dual climate control that causes uneven fogging.