no heat from dash ducts

[robbt]

I have 95' with some air duct issues. I have replace 2 of the three actuators, the third, above the gas pedal, has cracked gear but still works. The isssue is, I have no air from the dash ducts. There is air from the floor and from the defrost, when switched to defrost. I can switch the dial from floor to defrost and feel the actuator move from floor to defrost, but nothing from the center dash mount ducts. And it does stop in mid position or in a mixed position. From what other thread stated, one extreme is defrost the other extreme is floor, everything else is a mix. I already atemped to take apart the duct box, but stopped when I realized I hade to remove the a/c coil in order to remove the duct box. So I can not look at the actual door to see how it is operating, unless I cut into the plastic box, which I would also like to avoid. any ideas?

 

[samotahoe]

possibly the blend door motor is going out. its pretty common, and/ or the climate control switch. its the thing you move to change the air position. you will probably have to remove the evaporator

 

[robbt]

the climate control unit was replaced, which does bring up another question, but this problem existed before replacing the unit. My 95 unit had the exposed chip board style unit, at some time in mid 95 GM changes the style of unit as seen in 96 but kept the same wire harness, which ment they made a short adaptor harnes that connected the old 95 harnes to the newer units. In 96 the under dash wireing harnes plugged directly into the unit with three connectors, in 95 the harness was two connectors, the adaptor connnected to the 95 two connector harness and plugged into the three connector unit. Clear as mud. I did not have one with my new unit, so I had to fab one looking at pictures I could find of the back of these units with the supplied harness. Seams to work, except for the no heat for the dash diffusers, but this also occured before the replacement. The old unit did have a bad diode, which I though was the problem, hence the replacement. Problem still there.

so if anyone has a detail pic of that short harness or a layout of the wiring to verify the one I made, I would like to get that. I made have crossed some wires.

 

[monserhoe]

I also have this problem. Though I have not looked into it as much as you, but i would also like to see how this turns out. Will I have to tear out my entire dashboard to fix it?

 

[robbt]

there are some repair kits that allow to cut out a portion of the box to replace or repair the doors, then cover the hole made with some tin or using the piece cut out to patch the hole made. Otherwise, you have to evac the ac, remove the ac core inorder to remove the box to get to the doors. PITA. Since my ac is already drained, that will be my next step, when i have more time to have the vehicle down for a while.