99 Silverado ALL HEAT NO A/C OR VENT?

[borninabarn]

Hey guys,On my 1999 Silverado The heater works great but it seems to stay on heat.I have no vent and turn on the A/C and nothing there either just heat.I pulled the electric motor just above the tranny hump it seemed like it wasnt working and the wife said she could feel cold air on her feet while driving and I took it apart and looked at it put it back on and now it seemed to move? What do I need to check now to get the outside air(vent)working and hopefully the A/C.I called the salvage yard about the main HVAC control and they told me that most likely that wasnt the problem GM had other problems with the heater and A/C systems in these vehicles.Also was told about a MODE DOOR that you had to remove the dash to get at.Does my problem seem like a possible mode door problem? Thanks again

[kahjdh]

The blend door actuator sticks in these, there is a post somewhere on how to fix them. Mine will stick on heat and then if i restart the truck and move it to cold it will work until i go back to heat. Been buggin me but not enough to fix it.

[hogster3]

You need to remove the plastic kickplate under the
passenger side dash (4 screws). It's about an inch
above the tunnel (hump in the middle) on the right
side. It's about the size of a deck of cards. I
think there are 2 screws, one in the front that's not
too bad to get out, and one in the rear of the
actuator that you may not be able to see too well.
There is a shaft from the cold/hot air door that goes
into the actuator, so you'll need to slide it straight
down about an inch to remove it. Oh, and take off the
electrical connector.

Once that's out, take off the 3 phillips screws
holding the actuator together. Make sure you mark the
largest gear, driving the air door to the small blue
gear where the teeth mesh. Pop off the big gear, then
the next bigger gear, then the gear that mates with
the worm gear. You can use a screw driver to slide
the motor up and out of the housing, along with the
electronics board.

Then take the gear that was mating with the worm gear
and see if it's tight on the post it's supposed to sit
on. I reamed the gear out with a drill bit, by hand.

I'm not sure what grease they used in there, but there
was enough on the gears and electronic board to lube
up the shafts when I put it back together. Then put
it all back together, remembering to make sure the
alignment of the big bear to the small blue one is
correct.


I GOT THIS FROM A FELLOW MEMBER AND IT WORKED FOR ME. HIS NAME WAS RYAN. I GUESS YOU CAN REPLACE THE ACTUATOR, BUT REFILLING THE GREASE IN THERE WORKED FOR ME. IT IS NOT ALL THAT HARD TO DO.

HOGSTER

[phatiger]

I had same issue on 2000, replaced controler and no help. There are some wire connectors on pass side of dash (door must be open ) remove the access plate just like the fuse plate on driver side and unplug and replug the wires. worked for me. I have an extended cab and over time the twisting of the cab had pulled the wires loose. didnt need to change the ac controler .