Hi, I have a dilemma with my AC unit (and only the AC unit).
Whilst driving with the AC switched on, I can smell exhaust gases (and no doubt CO) getting into the cabin. If I turn the AC off, and use the recirc fan or freshair fans, no problem. I'm pretty certain that there is no smell with the heater on either.
Has anyone had anything similar or does anyone understand this circuit a little better than me and can attempt to guess where the ingress is occurring. I have looked in the engine bay with the car idling, but can't see/feel any emmissions from the pipes.
Fortunately, there isn't much call for AC at this time of year.
Please help, I haven't even written my goodbye note yet