My wife is having the same problem, only it's both knobs are not working now. The unit only works on Auto or defrost. I'm going to pull the knobs and panel here in a few mintues and I'll post what I find.
My wife is having the same problem, only it's both knobs are not working now. The unit only works on Auto or defrost. I'm going to pull the knobs and panel here in a few mintues and I'll post what I find.
Great thread everyone, I hope this helps!
DP
Well - I pulled the unit and found broken wires. I removed the ribbon cable and soldered 3 wires in place. No luck. I think the display now shows 75 degrees as the setting which it wasn't doing before, but turning the knob doesn't change the setting. At least 75 is a reasonable setting. I spent most of the morning working on it. When it didn't work the first time, I replaced the 3 wires. Didn't help. I think I'm going to take it to an electronic repair guy and see if he can figure out the problem.
I'm glad it's worked for everyone else...... I guess.....
You guys are great!!! My Dad just re-soldered the wires on my '03 Highlander for me, and I now have heat!!! The mechanic at the dealer said to try tightening the nut, and if that didn't work, the only other option would be a total replacement of the part ($751.00 plus labor!!)
Add one more satisfied user of this thread! I did the repair on my wife's Highlander yesterday. It was blowing hot air regardless of any other settings. Opened things up and found two broken wires. Replaced all three and voilą, we have control of the temp again!
One note. I had seen references to not being able to completely remove the back cover of the control unit because of the ribbon cable connecting the back to the circuit board. I immediately recognized that the ribbon cable goes into a connector on the main circuit board that allows the ribbon to be EASILY removed. There is a collar around that connector that can be pulled up ever so slightly using your finger nail. Pull it up from each end, it only moves about a tenth of an inch or so. Don't force the collar any further, it is permanently retained to the connector body. Once it is up the ribbon cable slides right out, allowing you to get the back panel out of your way. When you are putting things back together, be sure you put the ribbon cable all the way back into the connector (so none of the silver finger portion is visible) then gently push the collar back down. Be sure it is down all the way around the connector.
Thanks for the information on how to take out the heater control. I did that but no luck getting the proper temperature. I think I have to replace the entire part. Toyota has quoted $1100.00 ! No way I'm paying that. Does anyone know where you can purchase second hand parts for Toyota online? I have a '02 Highlander.
I've tried a couple of posts online for quotes but so far no luck.
try ebay, type in "highlander eps or acu" or any other configuration. when I had the heater problem i was thinking of changing the unit as well and i found it on ebay for $85. But this was a year ago.
they have genuine toyota parts but at half the price. dont go to the dealer or they will charge you an arm and a leg. while your replacing the unit clean it as well in the inside and change your ac air filter if you have a 2002 you probably have never changed it, its going to be dirty and GPW has it for $7 rather than $25 that other places have.
I attempted the 'wizzer' repair on my '03 Highlander....
Yes the 3-conductor ribben wire was loose and I attempted to solder it back. However, I attempted this solder job with a standard solder iron and fear that I have damaged the board. I have made two attempts at repair, reassembled, bu the the car still blows only hot air. Should I attempt a third time with a smaller solder iron or order new part? Anyone have the part number? Wizzer?
I love this forum! Thanks to all who shared their experience about the heater control. NEVONGUNTEN Regarding the check engine light - my 02 was recalled because this light is faulty - just had it to the dealer 2 days ago and it's repaired free of charge. (Guess they can afford to do that since there's about a thousand percent markup on the heater knob repair, right?)
Hi.
The diagnosis was right on about the Toyota Highlander control problem: broken wires.
I replaced wires and reassembled; good news and bad news. The heat comes on, but now I have an intermittent problem with 4 controls.
The recirculate, the ac button, the rear defrost and the mode of the heat (feet, defrost, etc.) The buttons/nobs work some time, but not others. If I tap the panel around the contorls, the buttons/nob work (some times). The right-most plug (from the front view) on the back seems to contain the wires for these buttons. I tried reseating the plug, but problem is still intermittent. Any one else with this problem?
Wizzer - your post has been most helpful with fixing my 02 Highlander's heat problem. However after I put all back together my vents aren't working. Only the dash vent works, no hands, no feet. Any ideas of what I may have done wrong? I've rechecked all my connections.
Thanks.
Tomhighlander - for your issue on controls sometimes not working after the fix. Did you remove that clear window* on the back panel and undo that inside ribbon connector between the two boards? That would be something else to check -- on mine I noticed the lower ribbon cable connection (on control panel circuit board) pulled out a little bit and even the snap down housing on the circuit board connector was disloged a bit.
Just had to push things back into place - very easy (but I never did experience the problem you are having)...
*Note: Clear window is made to come undone -- held down by some light, reusable adhesive. Just don't get the plastic window edges all dirty or dusty.
'03 Highlander here. My heater quit working too. We followed the information on this post. My wires were not broken. However, the dealer said it was the servo unit. I am having them replace that. $360 for that repair. Now I know if the wires break next, I can fix those easily.
Thanks for all the information. Awesome website.
Thanks to everyone on this site, I saved at least $1000 because of you guys. I live in Canada and had a loss of heat on my 02 highlander without any warning. I removed it which was a little difficult because I had the Toyota Navigation installed which is a bit longer (pushing the climate control wire harness further back) and so I could not access the wire without pulling out the entire chasis. I would imagine this to be much easier with the original radio. After pulling it out my friend reconnected new flexible wires, reinforced all the pins and put a locknut on the heat dial to ensure no movement. In addition you can reinforce the plastic clips behind to keep the switch in position. All said and done who the hell designed this poor switch, I bought a Toyota to avoid this very thing. If you live in the Gta and need help email me at mikecpf@gmail.com Thanks again Mike
I found a replacement manual heater/ac control online, bought it, had it installed and I still don't have any heat. The air is now colder than before I replaced the part. The part was brand new(bought if for $200) which was great but I'm totally frustrated & at a loss now about where to look next. Any ideas?
Re: Heater quit... sort of
desert sand 04 SR5 DC, aftermarket 2-tone leather, tint, mask, Line-X
You guys are great!!! My Dad just re-soldered the wires on my '03 Highlander for me, and I now have heat!!! The mechanic at the dealer said to try tightening the nut, and if that didn't work, the only other option would be a total replacement of the part ($751.00 plus labor!!)
Wdenis,
, type in "highlander eps or acu" or any other configuration. when I had the heater problem i was thinking of changing the unit as well and i found it on 
. while your replacing the unit clean it as well in the inside 
and change your ac air filter if you have a 2002 you probably have never changed it, its going to be dirty and GPW has it for $7 rather than $25 that other places have.
Linear Mode
