Just picked up the 2002 XJR a few days ago and noticed something peculiar as the temperature is dipping down outside. The A/C works great and does its job set to Auto. Everything is in sync. But today I noticed that after first starting the car and selecting Auto 72 degrees, it blows cold outside air at my face. Gahh! I read right in the manual that the car (and most cars I've been in with Auto control) should wait until the engine warms up to even turn the fan on. Another crazy thing, even with the car heated up, as I increase the temperature this fan blows cold air at the face level even faster as I increase the temperature until I hit about 82 degrees. Then the car finally kicks in the heat and directs it at my feet. The outside temperature displayed 58 degrees and I assume it is correct. I checked to see if there are any error codes stored in the climate control. It showed 0. Any ideas? I was thinking maybe the interior sensor was off? Because when I select 72 or there abouts, I know it is not yet that hot in the car. Thanks!

 

Try:
Turn Auto off.
Warm engine to normal operating temperature. Set climate temp to about 76 degrees. See if you get any heat withoput running A/C. After you are getting heat you should be able to run climate control on Auto.
V-8 engines take a while to warmup. Engine thermostat may also be sticking not allowing warm water to reach heater core.
Is the coolant at proper level?
Good luck

Burza 1998 VDP

 

Mine does the very same thing every now and then. Usually it's when I've got a chill and want the heat the most. Just did it last week when it was raining and 40 degrees. I need to figure this out too as it's only going to get colder and more miserable.

I'm watching this one.

 

Well, I've tried the things you mentioned and the car seems to be behaving for now. Can't figure out what got into it. I understand that V8's usually take their time warming up, but, most cars (including the Jag) will still wait until the coolant temperature is above a certain point to turn up the climate control fan so they don't freeze out the passengers in the winter time. I guess my car just had a random upset?

 

Now that it's colder here, mine get's upset regularly and it seems the only answer is to switch off Auto and the AC buttons. Once I take over with manual control I can crank the heat until I'm roasting.

I'm beginning to suspect the interior temp sensor is the issue. I'll start to diag this issue and report back on what I find.

Ken