dual climate control and 4WD

I have a 2004 Surburban and have two new issues to deal with.
The passenger side blows hot air all of the time, no matter what the dual climate control is set on for that side.
The dealer told me it was an actuator, and wants BIG $ to repair, because they say the entire dashboard has to be removed.
Is this true, and is it possible to do it myself within a reasonable amount of time? The part is $59.99 at a local shop.

I also have an issue with the push-button 4WD control, it will lock itself into 4WD-LO, and not move off of it. I have to re-start the truck 7-8 times to get it to reset. The "SERVICE 4WD" also comes on.
The dealer told me it was nothing and charged me $70 to "fix" the problem I later learned that all they did was to reset the computer.
When I called to complain, he said it must be a control motor that activates the 4WD. He also told me that this would require a lot of time to fix and again cost BIG $
Is this true, or is it just the switch. If it is the control motor, how difficult is this to replace?

And finally, is it just a coincidence that they both went bad at the same time, or is there some type of connection?

Unfortunately, the whole I/P does have to come out for the actuator to be replaced.. This job pays about 3 hours labor. With regards to the 4WD problem, the problem will take some time to diagnose properly.

I have the same problems, the passenger side blows only hot air, and the lights on the push button 4 wheel drive change each time I start the vehicle. sometimes neutral, somtimes 4 low and at times 4 high. For the most part it lights up in neutral (red light) but the strange thing is that while lit up it is always in 2 wheel drive. I have to cycle the ignition several times to get it to light back to 2 wheel.

Ideas on the hot air would be greatly appreciated with the outside temp increasing!

I believe the actuator is just a motorized damper. Given the time, you can probably just do that yourself. I've replaced one in the rear of our 2003 Tahoe and it was plug and play. Under the dash just means pulling off more stuff to get to it. I've got another one under the driver side dash that needs to be replaced as well. Both were made by the same manufacturer and both failed around 4 years/80k miles.

As for the "Service 4WD", we've had that on our Tahoe as well. From what I understand, it's usually the 4WD switch on the dash (Auto, 2H, 4H, 4 low)that causes the problem. Something (cracked solder?) causes a problem which the computer reads as a 4WD problem. I've heard just replacing the switch fixes it and only takes a few minutes to do. I haven't done it yet, but looks like the part is around $50-$75.

Yes, it's probably a coincidence that they happened at the same time. They're just getting older and the electrical controls that GM specified and installed were probably chosen for cost rather than long-term durability.