Question about 2001 GMC Safari

1 Answer

I have a 97 gmc safari. AC control is stuck on defrost. AC runs cold but will not switch from defrost to vents even when changing knob position. Any ideas what could be wrong?

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
  • 678 Answers

The HVAC system uses engine vacuum to open and close the blend doors. Check for a broken vacuum line in the engine compartment. It will exits the firewall left (passenger side) of center and will be a hard plastic line. With age and exposure to engine compartment temperatures they become brittle and break. It can be repaired with a rubber vacuum line that fits snugly over the line to reconnect them.

Posted on Aug 07, 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:

2 Answers

Vents won't blow hot or cold air. Comes from defrost and feet when you put fan on.


It's the vent actuator, it moves the baffle that changes the direction of the air flow.
Here is a video of a broken vacuum hose that creates the same problem.

It could also be a failed actuator.

Sep 19, 2016 | 1997 GMC Safari

1 Answer

My 2005 kia sorento will not switch from hot to cold and vise versa. the mechanic is saying its probably the "airdoor actuactor motor / mixer actuator. any advice and where to buy this part(s) for a g


Sorry for your troubles ,
Temperature Hand in dash reading NORMAL ?
Does it Turn Blue to Red if so is do you feel friction or restraint like your turning something rather than freewheeling (smooth fast turning) or Digital and or does it show that it should be warm and not cold ?
Does the TEMP change at all(even the least little bit could narrow the results down) when knob is turned?
POSSIBLE - The Actuator/Motor that switches the VENTS very well could be BAD , Temperature Switch / Climate Control Switch (hot to cold could be broke at the base and only allowing the knob to turn and not in the switch ) Thermostat may be stuck open (keeping the engine running cool and smooth but no heat , maybe just a slight TEMP change when switched from Cold to Hot ). The A/C Switch is pushed in or turned on or broke and is stuck ON
FIXES - 1st- Check FUSES - If Temp HAND Reads Normal it not your THERMOSTAT. - Change the Control Switch / Temp switch - Check A/C Button/Knob . AUTOZONE is my place of business they PRICE MATCH AS WELL!
Hope this Helps , Flaming Ratchets Auto Repair

Dec 05, 2013 | 2005 Kia Sorento

1 Answer

Air regulator valve on dash for heat and AC stuck in on position. Ram 2500, 2004.


The most common problem is a stuck or faulty blend door under the dash.

Feb 22, 2013 | Cars & Trucks

1 Answer

2006 focus cant get it off defrost


my knob broke from turning it because it became hard to turn--- i think the actuator is jammed or broke because even with a new knob, it turns freely and does not change selections.

May 03, 2012 | 2006 Ford Focus

1 Answer

Heat blows out at floor only and ac does not come on even though light Indicates it's on. Has rear defrost and light works..Also has recirculating air button . I'm guessing the whole heating control in...


I would first remove the fuse for the heater control head for one minute and then put in and retry.
The control head could have locked up on you with a volt spike. The rear defrost switch does not go through the same circuit in the heat as the hvac controls. Could be a broken know also.
Could also be mechanical linkage on side of heater box above accelerator pedal may have broken or popped apart. or if electrical motor control may be actuator.

#76-11-01: HVAC CONTROL KNOB SPINS FREELY (REPLACE) - (Oct 9, 1997) 999999995.gif SUBJECT: HVAC CONTROL KNOB SPINS FREELY (REPLACE ALL THREE KNOBS)
MODELS: 1996-97 CHEVROLET AND GMC M/L AND G VANS 1995-97 CHEVROLET AND GMC C/K TRUCKS
CONDITION:
SOME CUSTOMERS MAY REPORT THAT ONE OR MORE HVAC CONTROL KNOBS SPIN FREELY, RESULTING IN LOSS OF FAN, TEMPERATURE AND/OR MODE OPERATION.
CAUSE:
THE KNOB'S PLASTIC INNER SHAFT MAY CRACK WHEN FORCED AGAINST ITS STOP.
CORRECTION:
IF ANY ONE OF THE THREE HVAC CONTROL KNOBS EXHIBITS THIS CONDITION, REPLACE ALL THREE KNOBS WITH NEW P/N 16268157.
PARTS INFORMATION:
P/N DESCRIPTION QTY 16268157 KNOB, HVAC CONTROL 3

Sep 27, 2010 | 1995 GMC Yukon

2 Answers

2003 gmc Yukon 5.3 ..2WD air conditioner blows


A vacuum hose that controls the little door that switches where the air blows from is off, its gonna be a real chore the find which one and take the dash out to get to it, but you might get lucky and be able to look underneath the dash from the passenger side and actually see it, good luck

Jun 19, 2010 | Cars & Trucks

2 Answers

Vent selector stuck on defrost (knob turns - no change) 97 gmc safari


There's a good possibilty that you have a vacuum line off. When the heater controls lose vacuum, the heater will go into the defrost mode. There should be a small line, about 1/8 inch in diameter, that goes from the engine to the firewall. It's most likely on the passenger side.

Dec 28, 2009 | 1997 GMC Safari

1 Answer

97 Lumina...Switch stuck on defrost vent and


I had same problem . There is a vacuum resovoir tank located behind the left front splash shield . The vacuum line behind the battery goes to it . I removed two 5/32 screws just in front of the tire that hold the splash shield to the fender , carefully flex the shield away from the fender and take a look . I found the vacuum line had come loose , plugged it back on and everything works . Hope this helps

Dec 20, 2009 | 1997 Chevrolet Lumina

4 Answers

Heating / air conditioning control stuck to front defrost vents


There is a vacuum leak under the hood. Find the vacuum line on the passenger side where it comes through the firewall and follow it to the engine. You system needs vacuum to operate and without it the default setting is on defrost for safety reasons.

Jun 19, 2009 | 1999 Dodge Durango

1 Answer

2003 dodge caravan air vents will not change position?


I HAD THE SAME PROB WITH MINE I REPLACED THE HEATER CONTROL PANEL & IT FIXED IT

Nov 17, 2008 | 2003 Dodge Caravan

Not finding what you are looking for?
2001 GMC Safari Logo

404 people viewed this question

Ask a Question

Usually answered in minutes!

Top GMC Experts

yadayada
yadayada

Level 3 Expert

76164 Answers

Freddy

Level 3 Expert

1311 Answers

Colin Stickland
Colin Stickland

Level 3 Expert

22156 Answers

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

Answer questions

Manuals & User Guides

Loading...