Chalk up another another satisified Wizzer at home fix me upper. The resolution was dead on. Two wires were disconnected. Had to take apart the entire unit to see wires barely loose. Used the suggestion to unscrew 10mm bolts giving more room to work. I ended replacing the wires completely with 20 guage thin wire. Job was about 2 hours since it was my first time with this type of eletrical work. Wife already found ways to spend the $900 savings....
There is no way the engine would have come on because of this, correct? My engine light popped on right when my heater quit working. I took it to an auto zone to have the free diagnostic test run and it threw no codes. It actually just went off but came back on this morning.
I appreciate any help.[/quote]
I am new to this group, but wanted to share my experience with the check engine light that has come on a few times in the past 3-4 months in my 2003 Highlander. The codes that I got was for a vacumn leak and/or catylitic converter. The past couple of times the light went off by itself. I got a recall notice in the mail today saying that there is a problem with some computer logic.
I also appreciate the posting about the heater/AC problem. How difficult is it to get to the control unit?
Color me officially bummed. I took it all apart, did some detailed soddering, put it back together . . . and still no heat. I did notice two of the connections were broken, but seems it wasn't the issue. Many of the people on this post talked of intermittant or heat sometimes; I haven't had heat at all . . . good thing I live in Arizona.
Anyway, if anyone has any ideas on why my heat doesn't work at all, I'm all ears.
Thanks to Wizzer and Dfluitt for the posts and the photos. I'm one more happy guy who found this thread and fixed the heat problem in our 2002 Highlander.
The plastic frame that the heat control knob is screwed down to was broken, so I grabbed some epoxy, and glued everything together to strengthen the frame.
Looks like a pretty bad design to me. Kind of disappointed that Toyota doesn't acknowledge the problem and issue a fix.
Hi, all. Thanks for the info. I have a 2005 highlander with the same problem, broken wires, middle controller. The two outter wires. I just soldered it from the back leaving the broken wires. I used heavy tie from bread bag, works like a charm.
I actually have no heat. Just bought, tried heat couple days ago. Turned knob, never got heat. I've read all the different threads. Tried what each suggested, took unit out of dash, wires didn't appear to be broke. The board did look a little discolored. Could the board itself be the problem? What is the cost of the Temp control board? Are could it be something else?
Thanks,
Charlie
Thanks Everyone, especially for the photos! Last year, while my 2004 Highlander was still under warranty, the heat would come on full blast (while set to cold). When I picked up my truck from the Toyota dealer, they said they tightened the heater control. Huh? This made no sense to me (last year).
The problem just started again recently, and I found these posts. This weekend I took the dash apart, and sure enough, one wire was broken off, and was obviously touching intermittently. This kind of pisses me off, as the Toyota dealer didn't really fix the problem last year, they just stopped the switch from wiggling, and the wire managed to make contact. Clearly it was broken last year, while my warranty was still in effect. I'm glad I found this solution before forking out the big bucks for an un-necessary replacement.
Once you take out the bezzled dashboard part, how do you open the cover to see the wires?
I can't reach back to disconnect my central unit.
Any help on this?
HI,
Okay, once you have the bezel off, remove the six bolts that hold the heater control and radio in place. At this point the whole assembly can be pulled forward about six inches. Reach behind and remove the three sets of plugs that go into the heater unit. There is a locking tab in the top centre of each one, so I found I had to press it, while using a screwdriver on the sides to pry them loose.. they were pretty tight. Then remove the two phillips screws on each side of the heater control unit. Then you can gently pry the metal bracket that the phillips screws were holding tight, and pop the heater control module out. Now you can take it to your favourite workbench, or kitchen table. There are six phillips screws on the back that you need to remove... lift the back up about an inch, and look inside... there is a ribbon cable you should be able to pull straight out of the board.. then you can remove the back completely. At this point, along with the other pictures in these posts, you should be able to do the fix.
Tip: If you don't have great vision (I don't), the most handy "tool" I used was my Lee Valley lighted magnifying lamp thingy... the wires and solder joints are too small for me to work on without a good magnifier.
I actually have no heat. Just bought, tried heat couple days ago. Turned knob, never got heat. I've read all the different threads. Tried what each suggested, took unit out of dash, wires didn't appear to be broke. The board did look a little discolored. Could the board itself be the problem? What is the cost of the Temp control board? Are could it be something else?
Thanks,
Charlie
Hi,
Certainly the board could be defective.. I don't know if Toyota sells it by itself. Are you sure the wires are making good contact? I haven't seen anyone actually find that a board was blown yet... just broken solder/wire joints. Otherwise, hit the wreckers I guess. An alternative might be a good electronics repair place (these must still exist somewhere), as this appears to simply be a potentiometer... a variable resistor ... they could evaluate whether it was bad, and likely come up with a replacement.
Another satisfied customer - glad I found this site. Wizzer, like Eric Clapton, is a god. Thanks to all the others also that posted pictures and additional procedure info. My soldering was a bit scary, but the wires seem solid and everything worked. I disconnected the battery first since I've had issues in the past disconnecting stuff. The sunroof doesn't "auto" open and close - need to hold the button. Is there a way to reset the auto functionality? Thanks again.
ok, i have a variation of this problem in my girlfriends 04 highlander. when her A/C is on, sometimes it blows hot air like the heater is full blast.. she took it to an A/C place and they said the a/c panel you all are fixing is bad. same thing. 900 bucks total fix fromt the dealer. anyway, saw this post and did the three wire fix.. now the heat doesnt blow all the time like it was but the a/c only comes on intermittently. when i first hooked it all together it worked, then stopped shortley after. i have it all apart again and checked my work and all three wires are on ok. any ideas?? thanks. Bill.
ok, i have a variation of this problem in my girlfriends 04 highlander. when her A/C is on, sometimes it blows hot air like the heater is full blast.. she took it to an A/C place and they said the a/c panel you all are fixing is bad. same thing. 900 bucks total fix fromt the dealer. anyway, saw this post and did the three wire fix.. now the heat doesnt blow all the time like it was but the a/c only comes on intermittently. when i first hooked it all together it worked, then stopped shortley after. i have it all apart again and checked my work and all three wires are on ok. any ideas?? thanks. Bill.
update.. not good news.. now a/c isnt coming on at all. before the three wire fix, it was either a/c working or hot air blowing all the time.. now, it seems the hot air problem was fixed with the three wire fix, but the a/c isn't coming on at all.. i've had it apart 3 times checking out my work and checking if there could be another wire, part loose.. no such luck. any insite would be great. thanks. Bill.
Re: Heater quit... sort of
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