I have an '04 XJR with Nav. My question is when I have the climate control set on Auto, and it's cold outside, the fan kicks on high and blows cold air about 10 seconds after starting. My previous vehicle, '02 Olds Bravada, had an auto climate system, and it wouldn't kick the fan on until the engine was somewhat warm, i.e., it wouldn't blow cold air. Is it normal for the Jag to blow cold air or do I have sensor that could be bad?

 

I find this too, although fan doesn't come on full, but it still blows a bit. You might have a bad sensor, but I suspect it is poor software. Of course in England we don't get it quite so cold as the USA.

What is the external temperature reading on the dash when it does this ?

 

My VDP does the same thing so I let it warm-up for about 15 minutes before getting in.

 

Doesn't seem to matter. This morning it was -12 degrees F; on the way home from work, about 14 degrees; last week as warm as 30 degrees. The fan goes to it's highest setting within about a minute. I also found that when both driver and passenger are set at the same temp, the passenager side appears to have more air blowing out, and it is always cooler than the driver side.

 

hope that's not a sign that your heater core is going bad

 

That's what I'm wondering as well, but everything I've read talks about the driver's side not having any heat and the passenger side does. Mine is the opposite situation...

 

I always assumed that the initial blast was to ensure my warm, humid breath would not frost the windows. As mine is in defroster vent mode when it happens, it just made sense to me. Yes, the cold blast to the forehead is a waker-upper, but I've not had to scrape the inside of my windows ... yet.