Venting directly into the floor?

[Abaddon]

My truck has been venting heat AND A/C directly into the floor. Some of it still comes out the dash but about 80% of it blows straight into the floor. In fact, even when the heat and A/C is turned completely off, air comes in from outside directly into the floor. Kinda uncomfortable in the winter so I just keep the slider on heat so the air that seeps in is at least warm. Any ideas? I have all ideas a switch isn't closing or something but I didn't know if anyone else had dealt with this and had a quick, easy fix.

Abaddon

[Sparky2263]

What year is your truck? First gens (82-95) are famous for breaking the door hinge pins, actuators, etc.

[mrmidnight]

I know my 03 did that I asked about it at the dealership and they said it was supposed to, I didn't believe them, eventually I got used to it

[racerpat94]

my truck does pretty much the same thing, its a 97. temp works right, blower level(high/med/low) works, but it only comes on or off, you cant change the direction(only blows out the floor and defrost).

trying to sell it soon, need help ASAP! thanks!

[T Man]

Actually, its supposed to do this. In all of GM's infinate wisdom, they put a sort of "ram air" in their trucks to move cabin air around. Im not sure how it gets in, but its intentinoal

[Abaddon]

S-10s are NOT supposed to constantly blow my cold air directly into the floor. There's no reasoning for that at all. My 2000 Camaro certainly doesn't do that and it's a GM product. The guy at Advanced told me it's the blower switch and sold me one for $10. Now I'm gonna see if I can figure out how to install it. If it fixes the problem, I'll let everyone know. A mechanic friend of mine told me it was some type of vacuum switch that is located behind the dash panel where the A/C controls are located. This blower switch doesn't look anything like what my friend described. For $10, I'm willing to try anything once. Twice if it works. :)


Abaddon

[Sparky2263]

The blower switch will not fix a door problem. It only controls blower speed. What your friend is referring to is the vacuum switch, also located on the control head. It's the one with 5-7 vacuum lines going to it. Slight chance that might solve your problem, but doubtful.

As I said prev., most likely a door or actuator problem.

[Abaddon]

I'm willing to give his idea a try. He's been a mechanic for 30 years. Do you have any idea what the name of that vacuum switch would be?

[Sparky2263]

I call it the HVAC control head vacuum switch. That leaves no room for doubt as to which vacuum switch I want.

It's the 6 ported switch at the bottom of the pic.

[Abaddon]

How in the world did you get that picture? Do you have your own copy of the AllData software? :)

Do you know if LMC Truck carries that part? I may just order it. Thanks for the help!

Abaddon

[Jackb]

my truck has this same problem, but i can hear a slight vacume leak from behind the dash, well yesterday when i took it all apart to try and fix it i found out the revolver device was leaking air, so either fix that or deal with it, i have a lil coming out the top(def) some out the vents but almost all threw the bottom. So even with the vaccume leak at the dash could it still be the door?

[j894]

I would start from that control block where they all come together.
Is it leaking only when you move it or in just whatever position its in?

Also, check the lines your vacuum ball under the hood, Make sure they are all intact

[Jackb]

it leaks everytime when its on in any postion, if its off no leak

[Jackb]

ok my bad it does leak when its in the off position, if i move around the positioner switch a lil the leaking noise will go away, but about 80% of the blowing is still at the floor.

[Mikz86TA]

Pull out the control panel. Locate the vaccum source from the engine bay. Unplug it and with the engine running, put your finger over the opening to test to see if vaccum is present. If not, trace down the vac hose under the hood. could be a pinched,cut,unplugged or bad check valve on the hose somewhere. By default a GM HVAC system will only operate with the actuators in the afformentioned 'rest' positions. If you have vaccum, then check all fuses and move on to the actuators and doors on the HVAC air channels.

[Abaddon]

Just curious to see if anyone had fixed this for themselves. I hate my AC blowing into the floor but I can't find that part in the diagram.

[jtyler12]

My 93 s10 did the same thing. No air was coming out of the vents, all out on the floor and alittle out of the defroster. I tore into the system and discovered a plastic piece that attaches to the threaded acuator to a small hole in the door was broken. I "ridged" it using a small nut and a strong ZIP tie. When the acuator moves back the ZIP tie closes the door and allows a fair amount of air to come out of the vents.

[Abaddon]

Well mine is doing something weird. This is a pic I took with my phone:
http://img375.imageshack.us/img375/1245/ac1li0.jpg
The little aluminium clip with the spring isn't closing off the damper part underneath. I can force it over a bit and everything comes out the dash like it is supposed to. I wonder if that vacuum part on the side isn't pinching it off completely? Has anyone else ever had this happen?

I just took the spring off and forced it over (as you can see in the pic) for the time being but I'll have to change it back when winter comes around so it'll split the heat between the floor and the dash. I wonder if that spring is shot or if that part on the side isn't working properly?

As a side note, I pulled the air hoses off the part on the side and there was air moving through them so it's working properly (as far as I can tell) getting the vacuum down there. It's just not closing it off completely.

[Abaddon]

Anyone?

[Mikz86TA]

pic is kinda hard to see whats what. is the cable or vaccum operating correctly?