NG Looking for a little HVAC info 86 C10

[1970pelle]

Hello.NG. I'm liking the place.Lots of good info.My ?? first.1986 C10.My HVAC box has vacuum operated mode doors.There are 2 doors involved with vent air flow.There is a primary door and what looks like a secondary door.They are contolled by one lever from the vacuum actuator.There is a adjustment at the second door connection.I'm in need of how to properly adjust this door.Anybody have a factory service manual for truck using vacuum operated HVAC doors.I'm thinking 80 up.I have reentered the GM family after being gone since 1987.I bought my first and only ever new truck in 1983 C10 longbed.Kept it till 87 then sold it.At that time it only had 18k miles.Sold it for more than I paid for it.Now 2007 I found a 1986 C10 short fleetside,5.0L,4brl,700R4.Its a 1 owner truck from a 82 year old gentlemen,garage kept.A nice clean truck.It had a leaking heater core,which had been leaking for sometime.I found the carpet and juet soaked and the passenger side floor rusted.I had to weld in a 4X4 repair panel in the floor because of rust holes.The only rust holes in the whole truck.There is some surface rust in the bed and underneath.So I replaced heater core,new carpet and pad.Fixed all the burnt out bulbs.Updated the cluster so I could see at nite.Painted inside area silver(cluster).Plans are headers/w Duals.I have removed all failed vacuum hoses,pumps ect.Trying not to afend any green people.Also wanting to lower but still be able to tow a bike trailer or haul in the bed once in awhile.Paint wise I don't have to do anything now but in the furture I'm thinking of rather than semi flat black paint.A semiflat pewter with a small amout of chrome,wheels,sport bumper,mirrors.And dark tint to keep the HOT florida sun out.I apologize long first post.KA

[JJSZABO]

First of all - WELCOME to the site

I have an 86 c-10, but my HVAC door are not vacuum, their cable actuated, so I can't help you there -   But you are at the right place.

Sounds like a great truck, post pictures - PLEASE.

[Captkaos]

Welcome to the site!

[VileZambonie]

Remove glove box, then loosen cable attaching screw at the selector duct assembly.
Make sure the cable is installed in the bracket on the selector duct assembly, then place temperature lever in ``Cold'' position and hold while tightening cable attaching screw. All others operate on open or closed function.

[1970pelle]

Hvac doors are called.(1) temp door=controls air flow from heater core or A/C evap coil.Which is operated by a control cable.(2) mode door=controls air position on the dash.Defrost,vent,floor,biLevel.I need mode door adjustment which is operated by a vacuum actuator.Which is adjustable.Does anyone please have a manual??

[VileZambonie]

The door between the heater core and Evaporator is the blend door and is cable operated. The mode controls are vacuum controlled in either open or closed positions. The only reason you should need to adjust is if it's not openning or closing all the way which should never nned adjustment. What is your specific problem? No change in modes at all? The most common problem with these controls on these trucks is a loss of vacuum supply to the vacuum reserve canister in the engine compartment. Did you check that?

[1970pelle]

Man this is frustating in the HVAC box THERE ARE 2 DOOR THAT THE VACUUM ACTUATOR OPERATES.THEREIS A ROD THE CONNECT THE TWO DOORS THE LAST ONE ON THE CONNECTION HAS A ADJUSTMENT.I  NEED THE FACTORY PROCEDURE ON CORRECT ADJUSTMENT LENGHT OF THE ROD.i DON'T HAVE A VACUUM SUPPLY ISSUE,I DON'T HAVE A CABLE ISSUE.I WOULD HAVE STATED THAT. ALL I WANTED WAS THE ADJUST FOR THE MODE DOORS.SIMPLE.

[VileZambonie]

Man this is frustating in the HVAC box THERE ARE 2 DOOR THAT THE VACUUM ACTUATOR OPERATES.THEREIS A ROD THE CONNECT THE TWO DOORS THE LAST ONE ON THE CONNECTION HAS A ADJUSTMENT.I  NEED THE FACTORY PROCEDURE ON CORRECT ADJUSTMENT LENGHT OF THE ROD.i DON'T HAVE A VACUUM SUPPLY ISSUE,I DON'T HAVE A CABLE ISSUE.I WOULD HAVE STATED THAT. ALL I WANTED WAS THE ADJUST FOR THE MODE DOORS.SIMPLE.

Use a little common sense bud.  Try Google.com maybe you'll find better answers there

[Captkaos]

There isn't an adjust on the vacuum doors as Vile stated.  If it isn't working, you have a vacuum problem.

[1970pelle]

Here is a picture of the rod and connection I have asked about.The adjustment is at point B.

[VileZambonie]

I think it's pretty self explanatory Pele. Open = open - closed = closed.

[1970pelle]

Dude if you see there is a adjustment.Its not just open and closed.There are two doors.If not adjusted correctly they will hit each other.I just thought this being a chevy truck site.Someone would have a service manual close to the year of my truck.And would be kind enough to help with some info.Off the cuff replys don't work some times.If I'm not weclome here.Just say so.

[VileZambonie]

Everyone is welcome here you just don't have to be a rude jerk when people are trying to help you.

[VileZambonie]

start your engine and observe all of the different modes while you move the selector. When the actuator forces it all the way to the right diconnect the threaded rod from the clip. Move the shaft all the way to the right. Reconnect the clip. It shouldn't need to be moved unless someone was messing with it. The doors don't hit each other they move in tandem.

[Captkaos]

you are welcomed here but being rude to fellow members isn't.  You won't have to asked if you weren't welcome.  If you don't like someones answer politely ask for another opinion.  There is no need for shouting.