Question about 2003 Chevrolet Silverado 1500

1 Answer

Got a 2003 S-10 ZR2, the cooling and heat work fine but it's stuck in vent mode. I had the xfer case vacuum switch and the hvac control replaced which fixed the problem for about a week. Then the controller started hissing again and the vents qiut working. I pulled the vacuum trio off the switch and what do you know, dex III rolled out of the lines. Whats the right way to fix this?

Posted by on

Ad

1 Answer

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points

    All-Star:

    An expert that got 10 achievements.

    MVP:

    An expert that got 5 achievements.

    President:

    An expert whose answer got voted for 500 times.

  • Master
  • 1,608 Answers

After replacing the vac switch you also need to make sure and replace all the contaminated parts in the hvac system.This is per the service bulletin.You probably still had dex-3 in the lines and it finally worked it`s way back into the control head.Hope this helps.Good luck.

Posted on Nov 10, 2010

Ad

1 Suggested Answer

6ya6ya
  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

Hi,
a 6ya expert can help you resolve that issue over the phone in a minute or two.
best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
the service is completely free and covers almost anything you can think of (from cars to computers, handyman, and even drones).
click here to download the app (for users in the US for now) and get all the help you need.
goodluck!

Posted on Jan 02, 2017

Ad

Add Your Answer

Uploading: 0%

my-video-file.mp4

Complete. Click "Add" to insert your video. Add

×

Loading...
Loading...

Related Questions:

4 Answers

Air Con


no the pipes should not be cold and wet but if you just have stop using the aircon recently it will do that for a while till all the gas is out of the system so yes its sorta normal

Oct 02, 2008 | 2001 Chrysler PT Cruiser

1 Answer

Selector for air mode stuck on defrost


This is caused by a low engine vacuum, the engine vacuum is low when you accelerate, the HVAC system loses vacuum to the mode control vacuum switch and defaults to the defrost ducts for safety. You likely have a leaking mode control vacuum switch in the control panel of the heater AC system (HVAC).

Jun 16, 2016 | 2001 Ford Windstar

1 Answer

My heater only blows heat at the windshield and feet 1993 isuzu trooper. I added a picture to show what the controls look like. The switch to move where the air goes just clicks as if skipping teeth.


1000 points like the first ever here posting a photo.
shock, !
the heater (HVAC) controls for mode are failing
those are called dampers,
old car 93, they all have issues like this.
answering for USA cars only....
this car has good old cables x3
no vacuum bs. no computers. or damper motors$$$$
its just a cable and the FSM book calls that cable
so when you move the knob below the bell crank in photo 2 move
via the cable does it? if not cable is bad.
if yes, then does it go to the right location that bell crank below.
i used the red letter "S" for stuck
and arrow and X for vent mode..
in vent mode the bell crank turns, fully Clockwise
and lands on damper vent mode,
get vent and DEF working and all else (mode wise) works.



25945745-1ak23giogk35cldw332dzks5-2-0.jpg

25945745-1ak23giogk35cldw332dzks5-2-1.jpg

Nov 07, 2015 | Isuzu Cars & Trucks

2 Answers

I have a 2002 Chevy Impala the heat and air comes out all the vents at the same time can't direct it


After looking at the service info for the HVAC system for your vehicle , it sounds like your system lost vacuum somewhere ! The position of the mode doors determine where the air comes out at . The doors have vacuum controlled actuators , on the back of the mode switch vacuum lines are connected to it ! To check for vacuum at the switch you'll need to take HVAC control module out of the dash ! There is also a vacuum reservoir or tank under the dash near the HVAC assembly. You could look under the hood in the engine compartment an look for a disconnected vacuum hose from the engine intake manifold !
Step
Action
Yes
No

1

  1. Start the engine.
  2. Turn the blower motor fan ON and select an air outlet mode.
Does air flow out of the selected HVAC outlet ducts?
Go to Step 3 yes
Go to Step 2 no

2

Did the customer concern mention that the air discharges out the correct ducts at first, but then changes during higher engine RPM?
Go to Step 7 yes
Go to Step 3 no

3

With the engine running, cycle the HVAC controls through all the modes.
Does the air come out of the selected outlet ducts?
Go to Step 18 yes
Go to Step 4 no

4

With the engine running, take a vacuum reading at the manifold vacuum port that supplies vacuum to the HVAC control vacuum valve.
Is there engine vacuum?
Go to Step 6 yes
Go to Step 5 no

5

Repair the no vacuum condition.
Is the repair complete?
Go to Step 18 yes
--

6

Take a vacuum reading at the vacuum supply line at the HVAC control vacuum valve.
Is the vacuum reading the same as the engine vacuum?
Go to Step 11
Go to Step 8

7

  1. Disconnect the vacuum supply line from the HVAC control vacuum valve.
  2. With the vacuum gauge connected to the vacuum supply line, re-start the engine and turn the engine OFF.
Does the A/C system lose vacuum after turning OFF the engine?
Go to Step 8
Go to Step 11

8

Inspect for leaking or collapsed vacuum lines between the engine manifold vacuum port and the HVAC control vacuum valve.
Are the vacuum lines leaking?
Go to Step 9
Go to Step 10

9

Repair or replace the collapsed or leaking vacuum line.
Is the repair complete?
Go to Step 18
--

10

Replace the vacuum reservoir tank. Refer to Vacuum Tank Replacement .
Is the repair complete?
Go to Step 18
--

11

Using an external vacuum source, apply vacuum to the appropriate vacuum line at the HVAC control vacuum valve connector. Refer to HVAC Vacuum Schematics .
Does the actuator retract?
Go to Step 17
Go to Step 12

12

Inspect for leaking or collapsed vacuum lines between the actuator and the HVAC control vacuum valve connector.
Are the vacuum lines leaking?
Go to Step 9
Go to Step 13

13

  1. Disconnect the vacuum line from the actuator.
  2. Apply an external vacuum source to the actuator.
Did the actuator retract?
Go to Step 14
Go to Step 16

14

With the actuator disconnected, inspect the door for binding.
Does the door move freely?
Go to Step 16
Go to Step 15

15

Repair the binding door. Refer to the appropriate repair.
?€¢
Defroster Door Replacement


?€¢
Mode Door Replacement


?€¢
Recirculation Door Replacement

Is the repair complete?
Go to Step 18
--

16

Replace the vacuum actuator. Refer to the appropriate repair.
?€¢
Defroster Valve Actuator Replacement


?€¢
Mode Actuator Replacement


?€¢
Recirculation Actuator Replacement

Is the repair complete?
Go to Step 18
--

17

Replace the HVAC control vacuum valve. Refer to HVAC Control Vacuum Valve Replacement .
Is the repair complete?
Go to Step 18
--

18

Cycle the HVAC controls through all modes to verify proper operation.
Did you correct the condition?
System OK
--
Hope this helps an good luck !

May 08, 2015 | 2002 Chevrolet Impala

2 Answers

What diverts air to defrost. Air comes out vents and floor. ac works and heat , but won't go up to dash vents. The flaps are working.


You just THINK the flaps are working, but apparently the top vent is not. These multiple flaps are controlled by vacuum and you have a line off to that particular flap. This means the flap won't open and the vacuum leak, whether you can hear it or not, is making you lose MPG also, though slight. The vacuum line could be cracked or disconnected from the flap or at the vacuum block on the back of the lever unit.

Aug 18, 2014 | Cars & Trucks

1 Answer

2002 Blazer ZR2 - when set to floor heat only HVAC works fine until going up a hill or heavy acceleration. This seems linked to a vacuum issue but where would I begin to look? All heat and AC positions...


Hi, there is a plastic line that runs from the mode switch to the intake manifold or reservoir. The small hose that connects that line to the intake is often leaking. If not that, trace the line thru the firewall to the switch. Take the bezel off and pull the control panel out to see the hoses. start the truck and listen to the back of the mode switch for leaks in the connection or the switch itself. If there is a "T" in the line near the switch, check that too. Finally, trace the lines to the mode door vacuum motors to see if any of the mode motors or attach hoses is leaking. In each case, you've got to have the engine running, and it's basically a listening technique, since the leaks is small. You can tug on the lines to see if that will make the hiss louder. A small leak like that is hard to find. Good luck!

Jan 16, 2011 | 2002 Chevrolet Blazer

1 Answer

Had the battery changed, but now the (heat) vents in the top of the van and the floor vent (heat) does not work - only cold air comes out. Also, the heating/cooling dial lets it get hot midway on cold...


Try this calibration procedure and let us know if you have more questions:
  1. Start the vehicle.
  2. Wait 40 seconds for the HVAC control module to self-calibrate.
  3. Verify that no DTCs have set as current DTCs.
  4. Clear all DTCs.
  5. Place the ignition switch to the OFF position.
  6. With the Mode knob in the PANEL position, press and hold the AC button for 5 seconds.
  7. Rotate the Mode knob fully counterclockwise.
  8. Rotate the Mode knob fully clockwise.
  9. Rotate the Mode knob fully counterclockwise.
  10. Release the AC button.
  11. Wait 40 seconds for the HVAC control module to self-calibrate.
  12. Start the vehicle.
  13. Verify that no DTCs have set as current DTCs.

Nov 14, 2010 | 2005 Pontiac Montana SV6

1 Answer

I have just replaced my thermostat housing bleed the radiator and i still got no heating the thermostat is brand new


MAKE SURE BLOWER MOTOR OPERATING IF NOT CHECK FUSE AND RELAY.ALSO CHECK HVAC FUSE THIS CONTROL HEATER + AC CONTROL SWITCH AND MODE SELECTION FOR OPENING AND CLOSING HEATER DOOR OR HEATER CONTROL VALVE AND AC+ DEFROST AIR DOOR.IF BLOWER AND HVAC FUSE OKAY.IF YOU HAVE MANUAL HEAT CONTROL MAKE SURE MODE SWITCH IS RECEIVING VACUUM. YOU HAVE TO REMOVE HEATER CONTROL SWITCH AND CHECK TO SEE IF GETTING VACUUM GETTING TO SWITCH LOOK FOR BROKE DISCONNECTED VACUUM LINES IN THE DASH AREA.IF YOU HAVE CLIMATE CONTROL.YOU COULD HAVE A FAULTY ELECTRICAL HEAT DOOR ACTUATOR.SOME CLIMATE CONTROL CARS HAS THE CLIMATE CONTROL PROGRAMMER HAS TO BE REPROGRAM BEFORE THE HEATER AND AC WILL WORK AGAIN.YOU NEED A DEALERSHIP SCANNER TO CHECK IT OUT.BUT IF YOU HAVE MANUAL CONTROL CHECK TO SEE IF YOU GETTING VACUUM.IF YOU GETTING VACUUM AT HEATER DOOR VACUUM ACTUATOR OR HEATER CONTROL VALVE EITHER ONE OF THOSE COMPONENTS COULD BE FAULTY.WARNING YOUR VECHICLE HAS AIRBAGS YOU HAVE TO DISARM THEM BY REMOVING FUSES WAIT 20 MINUTES BEFORE WORKING ON DASH AREA.YOU HAVE TO CRANK CAR UP TO CHECK TO SEE IF YOUR HVAC GETTING VACUUM.

Oct 24, 2010 | Renault Sport Cars & Trucks

3 Answers

Hello I'm having heat problemes. so far i flussed the system, still having no heat, Changed radiator and heatercor,Changed thermostat,Changed heat sensor,Now pleanty of heat acording to gage but still cold...


did you check the vacuum source of all heater controls inside the dash? maybe the actuating door valve has a leak due to an air line. also the selector mode switch could be bad

Feb 07, 2010 | 1995 Ford Windstar

Not finding what you are looking for?
Cars & Trucks Logo

Related Topics:

53 people viewed this question

Ask a Question

Usually answered in minutes!

Top Chevrolet Experts

yadayada
yadayada

Level 3 Expert

76109 Answers

Colin Stickland
Colin Stickland

Level 3 Expert

22156 Answers

Jeff Turcotte
Jeff Turcotte

Level 3 Expert

8270 Answers

Are you a Chevrolet Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides

Loading...