Old Blue

My 99 Silverado C1500 LS won't blow air from the dash vents but when I select the other settings will blow air from the defrost, rear console and all floor vents.
I did a little cyber searching and found this to be a common issue with our trucks and the information I found said to check


heater dash control panel
Mode door actuator
Mode door
Blend door actuator
wiring


last thing I want to do is to be playing the guess game wasting money on parts I don't need so I'm hoping someone here
whose had this same issue can narrow down what I should be checking or point me in the right direction ?
Thanks in advance for your advice.

oldchevy

I had a 1999 Silverado LS and the problem was the mode door actuator. I changed that and the problem went away. They are plastic and break over time. You can't know for sure until you get in there and check it out.

Old Blue

Thanks for responding ......looks like a good place to start and at $43 delivered to my door It looks like I'll have to dig in and get it swapped out this weekend. I'll let you know how things turn out.

Old Blue

Okay guys...here's where I'm at with this. Still need some advice
I decided to buy a new unit (DORMAN 604-113) and remove the old and install the new. All went well until it was time to separate the old Actuator from the Actuator Cam. It simply would not budge and ended up coming out as 1 unit sliding off the paws under the dash which are a royal pain to see & locate to re-install. I had to gently tap the old Actuator out of the Actuator Cam at the gear spline and install the new Actuator. But now I cant seem to locate any information online showing a diagram as to how the Actuator Cam is installed which brings me here. Hoping someone can point me to a diagram or illustration so I can finish the install and put my dash back togeather. Thanks in advance for your tips and info. It's greatly appreciated. Above is a pic of the parts I'm referring to and they mount under the dash to the right of the steering column on my 99 Silverado LS1500 Ext Cab.

Old Blue

Old Blue

Update......


After getting some better lighting and a closer look under the dash it became pretty obvious that the Actuator Cam had to be installed 1st and then the Actuator. It took several attempts to get both lined up with some grunts, groans and not so good words but I got it done. Connected the harness, fired up the truck, turned on the AC and air now flows from the vents when selected and all the other settings work as they should.


Thanks for the responses guys

Stob

I know this is an old thread, but I have just gone through this and it is NOT as simple as Old Blue says. "...grunts and not so good words..." doesn't even come close to the frustration of accessing this actuator and motor, much to kind.

I searched all over to find info on remove and replace, and nothing really conveys how difficult it is to get to it, not to mention how to get it back in, both door pins engaged in the cam and held in place while you try to get the motor pushed back on with the 2 screws aligned. Oh, and that top screw is almost impossible to get a socket on with a universal.

I'm 67 and just can't bend and contort as easy as I used to. This is one time I would have paid to get it changed, but it got done.

NIOMARVIN83

It’s absolutely not easy, and it's not about age, it's about skills only. I tried to do it by myself, but my patience finished after 30 minutes. Good for me, I have a time-tested nice service center at wall work. I paid to get it changed, but it got done and no worries about quality