I was on a trip last week and my wife was complaining of cold air comming in by her feet. We switch places and around 70 mph, sure enough, there was a pretty good blast of cold air comming in between the heater and the passenger side cab wall. I looked as much as I could inside and out and without taking the heater out, I could find anything. Has anyone else had this problem? Temps were around 20 degrees. Didn't notice it when it was warmer.

I have the same problem in my 01 c/c i checked it out like you and came up with nothing please let me know if find anything out. thanks dave

I also have an 01 ext. cab, maybe it was something in that year. I'll sure let you know if I come up with anything.

Manual or Full Automatic Climate control system?

I would say manual? Not sure what you mean by fully automatic.

A manual control system just has sliders to adjust the heat.

A fully automatic climate control system has 2 knobs, one for the driver and 1 for the passenger and has a digital readout for the temp.

I believe the manual system has slider controls for both the driver and the passenger.

I am not too familiar with the manual system as I have the auto climate control system.

Also, what year is your truck and trim level?

It may be something as simple as the passenger side is turned down and the driver's side is turned up. The system will do it's best to accommodate both parties.

I had the same problem in my '00 1500. I just thought it was my wife until I rode on the passenger side one day. I found that the problem was the door that you remove to change the cabin air filter. I pushed the cover into place and put some duct tape on it to seal it. The problem has since gone away.

Ask your dealer if they have ever heard of this....Here in wisconsin, when I was with the chevy dealer, we had lots of these come in for this problem...Service used a product from 3m to fix it (of course, 3m doesn't make it anymore:mad: parts number was 08505) but what it amounted to was a flexable sealing material that they pressed into place to seal these cold air leaks...one of your local dealers may have a similar fix for your trucks.....

To answer DavesDmax, I have the manual system. Just one temp control not dual. My truck is an 01 LT package. I haven't talked to the dealer yet, but will this week. Also, the air is not comming from the cabin air filter door. Thanks Wishihadadiesel!

There was a TSB out for it. I think it was a missing foam seal between the firewall and the blower. The flip side of the problem is hot air to only one side of the cab when you select 'floor.'

Ask your dealer if they have ever heard of this....Here in wisconsin, when I was with the chevy dealer, we had lots of these come in for this problem...Service used a product from 3m to fix it (of course, 3m doesn't make it anymore:mad: parts number was 08505) but what it amounted to was a flexable sealing material that they pressed into place to seal these cold air leaks...one of your local dealers may have a similar fix for your trucks.....
It's called "dumb gum". It's used by auto A/C shops to seal around the firewall pentrations. I think Napa sells it by the box.

Talked to the dealer today, he knew what I was talking about. He told me that the seal at the air intake for the heater/AC tends to leak allowing the cold air in. He made it sound like it was an extensive job to get in there and fix. ??? I'll post after I get it back.

Getbent, what happened? I just returned form WY with my son and we both found that the passenger side could not get comortable without making the driver miserable. Not so much a draft on the passenger side, just seemed like inadaquate heat. Not sure if the TSB listed in the past relates, it states for '01 trucks.