1997 XJ6VP Center Air Vent

I just purchased a 97 XJ6VP with 35000 miles. The car is beautiful being garaged from new. I drove it about 500 miles home yesterday with absolutely no issues. One concern is the volume of air coming out the center air vent when I have the button pressed for face level. The AC was ice cold but for a minute or two, the volume of air out the vent was forceful but then would suddenly cut back even though the fan motors continued to run at the same speed. On my 95, if I choose the same setting, it will give me the same volume of air until I manually turn the fans down.

Any help sincerely appreciated.

Richard

Not having any responses to my original post, I did the self-test but no codes showing. Playing with it more, if I press one of the other buttons such as “face/footwell” and press the “face” button again, I get full face volume for about a minute then back to maybe half. It seems like the vent is fully open and then closes partically???