Question about 2005 Toyota Highlander

2 Answers

A/C will suddenly send out heat. Fiddling with knobs seems to help. What's wrong?

I recently purchased a used 2005 Toyota Highlander. When I have the a/c on, it will suddenly send out hot air until I fiddle with the knobs. What's going on? 2005 Toyota Highlander, heat coming out of dash vents and floor even when the fan is in the off position and the temp control knob is in the cold position. Same happens when turning a/c on. Could this be a knob problem? I have a 2005 highlander, when my a/c unit is on it cools for a good minute. Suddenly it is blowing out hot air. When I start rotating the a/c dail back and forth it starts back blowing cold air again. Sometimes when I am driving on ruff pavement it starts blowing out hot air also. But when I rotate the A/C button to the coldest temp, it starts back blowing cold air for a minute or two, then right back to blowing hot air.

Posted by on

2 Answers

  • Level 1:

    An expert who has achieved level 1.


    An expert that has over 10 points.


    An expert whose answer got voted for 2 times.

  • Contributor
  • 1 Answer

You have a broken wire connection between the temperature control knob and the circuit board behind the center dash console. Vibration causes the failure and once the control knob gets loose the solder connection fails.

For someone that knows how to remove the dash unit and can re-solder a couple of new wires this fix should take no more than 1 hour. Make sure that you apply loctite to the heat control knob spindle nut when you re-assemble it.

The dealer quoted me 750 dollars to fix this issue and I found out that it's a common failure for this year. I fixed mine virtually for free but it took some tools and about an hour of my time.

Posted on Jun 21, 2009

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points


    An expert that got 5 achievements.

    Vice President:

    An expert whose answer got voted for 100 times.


    An expert that has over 500 points.

  • Toyota Master
  • 358 Answers

From what you describe it seems like it may need a a/c heater control asy.I checked for a/c control bullitans and there is not any at this time.

Posted on Jun 02, 2009

1 Suggested Answer

  • 2 Answers

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

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.

Posted on Jan 02, 2017

Add Your Answer

Uploading: 0%


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



Related Questions:

1 Answer

My toyota highlander when the thermostat is on cool all the sudden hot air will come out and then it goes back to cool again if i move the control knob..

Keep it pointed in the cooling direction... or it may be a manufacturer issue. Toyota dealer can/might help too. Probably for free. Sounds like a relatively simple issue.

Apr 19, 2011 | 2005 Toyota Highlander

3 Answers

My 2005 highlander has the knobs that control the heating and coolinf fan, temperature and vent. The temperature control knob is randomly changing to hot when it is set on cold and visa versa when you turn...

Hello, and welcome to FixYa, Please allow me to assit you.

The issue that you are having is indeed in the control assembly. Yes, it does cost over 600 dollars to replace it.

However...if you have any soldering skills, or know someone that does have soldering skills, you can fix this problem yourself.

All that is wrong with the controller is a broken wire going from the small printed ciorcuit board that the knob is located on, to the controller's main PC board. Removal of the controller, and a disassembly will show you the broken wire. Just solder the wire back to the terminal that does not have a wire on it will fix you right up, AND save you 600 dollars!!!

Thanks for choosing FixYa for advice today.

Mar 30, 2010 | 2005 Toyota Highlander

1 Answer

2005 Highlander .... turned on defroster to clear foggy windows then switch to reg "body/feet" heat ... but heat would not/does work ... help!!! it worked fine yesterday HELP

They had problems with the heater switch loosening up. Sometimes it can be fixed sometimes the whole heater assy has to be replaced. The heater knob will pull off. Pull that off and then there is a nut that should be loose. Tighten that nut but be careful not to over tighten because you break this piece and you will be buying the heater assy. After you tighten that reinstall know and see if that fixes it.

Jan 20, 2010 | 2005 Toyota Highlander

1 Answer

Hot/cold air blowing out when A/C unit is on

You can tinker with it, if you know how to get behind
the knob and look for the loose wires and re-solder it
in place.

Sep 25, 2009 | 2005 Toyota Highlander

1 Answer

2005 highlander heater problem

I'm glad I could help. I'm reposting the solution below in case anyone needs it in the future. Please be sure to rate it for me!

Pull the temperature knob off and verify the thin 12mm nut is installed and tight behind it. I have seen several of these loosen up allowing the knob to turn but intermittently have no effect on temperature.

Sep 11, 2009 | 2005 Toyota Highlander

2 Answers

A/C will suddenly send out heat. Fiddling with knobs seems to help. What's wrong?

The nut that holds the middle knob has gotten loose and the knob (which is probably loose) has caused a wire behind it to break. I found the fix on the internet with details and pictures and all you need is to take the cover off and solder the broken wire back. I don't know where the website is now but search "toyota highlander blows hot and cold" and you might find it. Good luck. don't let dealership put a new control panel in.

May 10, 2009 | 2001 Toyota Highlander

1 Answer

Highlander no heat

Pull off the heater control knob, and tighten the nut that is behind it.

Jan 30, 2009 | 2005 Toyota Highlander

2 Answers

No heat 2005 highlander

try pulling off the temp. control knob and tightening the shaft nut.

Dec 21, 2008 | 2005 Toyota Highlander

Not finding what you are looking for?
2005 Toyota Highlander Logo

1,713 people viewed this question

Ask a Question

Usually answered in minutes!

Top Toyota Experts


Level 3 Expert

75822 Answers

Colin Stickland
Colin Stickland

Level 3 Expert

22156 Answers

Jeff Turcotte
Jeff Turcotte

Level 3 Expert

8202 Answers

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

Answer questions

Manuals & User Guides