1996 s10 4x4 heater problem

[LV1]

Hi all, My heat and ac controls on dash went bonkers. All I get now is ac and the cold air is coming out the defrost and floor vents, When I adjust the knob on dash to to heat , defrost,any vent all I get is ac threw the defrost and floor vent Any ideas? Thanks

[MT-2500]

Originally Posted by LV1

Hi all, My heat and ac controls on dash went bonkers. All I get now is ac and the cold air is coming out the defrost and floor vents, When I adjust the knob on dash to to heat , defrost,any vent all I get is ac threw the defrost and floor vent Any ideas? Thanks

If vacumn controls check for vacume to them.
If automatic control check havc for codes,

[LV1]

Hello, I'm not sure how to check the vacuum.Checking other things, I found one hot heater hose and the other was cold. Plugged heater core probably, So I did a back flush on it. Now I have heat plus ac but only on the floor and defrost vents. I took the climate control panel loose from the dash and on the back were the vacuum line slip in, there is one pole open with no hose, is this suppose to not have a hose or be plugged? There are 5 hoses plugged in now.

Larry

[MT-2500]

Originally Posted by LV1

Hello, I'm not sure how to check the vacuum.Checking other things, I found one hot heater hose and the other was cold. Plugged heater core probably, So I did a back flush on it. Now I have heat plus ac but only on the floor and defrost vents. I took the climate control panel loose from the dash and on the back were the vacuum line slip in, there is one pole open with no hose, is this suppose to not have a hose or be plugged? There are 5 hoses plugged in now.

Larry

There is usually a open port for venting.
Engine vacuum usually goes thew a vacuum tank under hood.
Plastic and rubber hoses.
Make sure no hoses off or broken.
Check for good engine vacuum at and to and to heater controls from tank.

[MT-2500]

Originally Posted by MT-2500

There is usually a open port for venting.
Engine vacuum usually goes thew a vacuum tank under hood.
Plastic and rubber hoses.
Make sure no hoses off or broken.
Check for good engine vacuum at and to and to heater controls from tank.

No. 6 port black\gray is hose and vacuum to controls. Good old vacuum gauge helps test for good full engine vacuum.
Around 16 to18 in. is good.

[LV1]

Hi, Checked Vaccume and I'm reading 20 on my gauge. One other thing I noticed is the light behind the temperature dial doesnt light up like it used to. Possible that the control unit is faulty? Thanks