2002 Toyota Highlander AC main control

Search for my prior solution under Nitram2. It's almost always broken wires in a 3-wire harness feeding the knobs. Toyota will skim you close to $1000 for this, claiming that you need to replace the control board. It's an easy half-hour soldering job.

Hello. Welcome to FixYa. Please allow us to assist you.

You have one of two possible problems.

1) The retainer nut for the temperature control is loose

2) A wire is broken from the temperature control sub-circuit board to the main circuit board.

If the retainer nut is not loose, the unit can be repaired. This will entail removal of the heater control from the dash, disassembling it, identifying the broken wire, and resoldering the broken wire back in place.

If you are not skilled in disassembling the dash and the heater control, and not skilled in soldering, this job is best left to a professional. The alternative ti repairing the broken wire is costly. The replacement control is roughly 900 dollars, plus installation. A qualified technician can repair your control in less than 2 hours.

If you need further assistance, please feel free to get back to me.

Thanks for choosing FixYa today.

Hello. Thank you for requesting me. We have been seeing a large amount of Highlanders with temperature control issues. A replacement control is in the proximity of 900 dollars. After the fifth one sold, and some really unhappy customers, I decided to see what the issue was that was causing the failures. It turns out that the problem is nothing more than a broken wire of two. If you are handy with tools, and can use a soldering gun, you can fix it yourself. The problem with the controls needing replacement is a broken wire or two at the circuit board that controls the temperature (the center knob). This is unfortunately common, albeit an expensive repair. Here is how you can fix it yourself: What you will need: Pencil-type soldering iron, rosin core solder, a Phillips screwdriver, a 10 millimeter socket, extension and ratchet. First, remove the plastic fascia that surrounds the radio/heater-AC control. (Be careful to not crack it when removing it.) Next, remove all of the 10 millimeter bolts that holds the Radio/AC-heater control assembly to the dash panel, and unplug all of the wiring connectors. Next, remove the three control knobs on the Heater/AC control panel, and the silver nuts that holds the controls to the panel. They pull straight off. (Under the center knob, you will probably find a loose nut, this is what caused the wires to break, the control is loose in its holder.). Next, turn the assembly over, with the back facing upwards. You will see a rectangular black box. Remove the screws that hold the black box onto the back side of the front of the control panel. There will be a ribbon-wire connector that will need to be removed from the front panel; be careful when removing the black box?s connection, and take care to not damage the connection ribbon wires. Next, remove the entire circuit board from the panel cover, by removing several Phillips screws, this will allow easier access to the control board that needs the wire(s) soldered. At this point, you have two choices: You can solder the broken wire back onto the control?s board, or, if you desire, you can remove the ribbon wire, and replace it with different wires; personally, I choose this path, and I use telephone wire, three lengths, that I strip and solder to both locations, each of the three on the main board and the other end on the control board. Either way will work, as long as you solder the wires back properly, and avoid any possible shorts by allowing the solder to touch an adjacent lead. Once you have soldered the broken wires from the temperature control board back on to the main circuit board; reassemble the parts and refit it assembly to the dash. Thanks for choosing FixYa for assistance today; I hope that this helps you out, and saves you a bunch of money.

Hi.

I assume that you are having issues with the heat controller; which is a very common problem. And, it costs over 900 dollars to replace it, when all is wrong with it are 2 broken wires.

Unfortunately, you have to completely remove the heater controller from the dash, and completely disassemble it to gain access to the 2 wires that need soldered, it is impossible to gain access to the wires with the unit in the dash. When you get it apart, look for 2 broken wires at the sub-PC board (from the knob) going to the main PC board. Also, to avoid having these wires break again, make sure that the nut behind the knob is real tight; if it is loose, it allows the board to rotate, and snap the wires.

I would recommend that you reserve a day for this project.

Thanks for choosing FixYa for your solution.

Yes, I know the answer. The wires on the heat control knob have come loose from the main circuit board. It is a ERY expensive part to replace. However, you can repair it, if you, or somebody you know, can solder wires. You will need to remove the AC amplifier assembly, and disassemble it. it is apart, you will se 1 or 2 broken wires on the control knob circuit board that connects to the main board. Resolder them, and you are good to go.

You have a broken wire on the heater control potentiometer. You can either order and replace the control, which is expensive, or you can remove the control, and disassemble it, and re-solder the broken wire. We do this all of the time; resolder the pots bacjk on to the main PC board.

You have one of two possible problems.

1) The temperature shaft retention nut is loose behind the knob

2.) The wires to the potentiometer part of the temperature may be broken.

Either one is common to this vehicle. The replacement of the AC controller is about 900 dollars. If the wires are broken, they can easily be reattached to the circuit board via soldering. What you would have to do is remove the control box from the dash, and disassemble it. Once the unit is apart, there are 3 wires from the temp knob to the circuit board that need to be re-soldered. The unit CAN be repaired, as opposed to the expense of replacing it.

You can save a LOT of money by fixing it yourself.

All that is wrong with the knob are broken wires from the knob's PC board to the main PC board on the AC control.

All you have to do is remove the AC main control, take it apart, and resolder the broken wires from the PC board with the knob on it, to the main AC pc board. There are 3 wires, any number could be broken.

If you take it apart and solder the broken wires, this WILL fix your issue. Just make sure you put the wires back exactly where they go.

A FIXYA rating (4 blue diamonds) would be most appreciated for my assistance.

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