Pricey dealer AC repair - thoughts? (1 Viewer)

[Walking Eagle]

Dang, wish I'd seen this thread earlier. I've had the same problem - only mine comes back on. I had the same problem last year, goofed around with getting the right amount of 134a in the system, and the problem went away, I was dumb and happy. It happened again this summer. Worked fine on the way to work, then when I started it up to go home, nothing - whole middle row of lights was dead and no fan. I replaced the control unit (I went used as even CDAN price is over four bills). Worked fine for a while, then the other day it went out again. Then on again. Then I went to the bank and it worked when I turned the engine off and didn't when I re-started it. But 5 min down the road it came on.

It's quite the mystery. I posted a question about it last summer and got no good info. Did the same this summer 1st time it happened, and didn't get a single response.

https://forum.ih8mud.com/showthread.php?t=104673

My brother forwarded me an e-mail from a friend he sold a control unit to, and he took the auto switch from his old unit, and put it on the standard LC unit and switched the switch in the back to M from A (manual to auto). Hopefully he won't mind me quoting him here

'When I had problems with my AC panel, my fans were not working and the buttons seemed to be stuck on. I checked the blower motor, fuses, relays, and other things connected to the ac circuit but my problem was with the 54 pin AC amp.

Ask you brother to check the AC amplifier that is located on the firewall on the driver side near his right knee. He may need to remove the plastic vent to get access. The AC amp has 3 plugs (54 pins) connected to it and is about 4"x 6" x 1". My amp was fried due to water intrusion. When I removed the cover of the AC amp I noticed a few of the resistors on the bottom that were FUBR. There was still some water in there when I removed it. This was due to a leaky seal on the bottom of my windshield and I would notice water on the floorboard after it rained. I have since resealed my windshield with clear RTV and I have no more leaks. I replaced that amp from a lx450 and everything works ok.

Hope this helps.
Bolon'

That's what I'm going after next. Kinda hoping it stays working for a couple more weeks so it's not so hot out when I do it. Somehow I don't mind doing mods on the outside of the truck in the hot, but crawling under the dash to do stuff I don't want to do in 100 deg. heat. If you get to it first, let me know if it works, if I get to it first, I'll do the same.

Heath

 

[heckler]

I hope i am not too late.

I had the exact same problem with my truck, it was caused because the computer that controls the climate control got wet. It took a while to figure it out and i remember that toyota quoted me 700 for a new one. I found one for $75 off a wrecked lexus. I remembered i found a couple off of car-part.com for 90 but you will have to call them and give them the part number, which i forgot. But the part is located right above your right foot and it is in a 4" x 4" beige box with two or three big plugs going into it. i hope this helps, send me a PM if I confused you.

 

[Dawnpatrol]

Interesting thoughts, thanks Heath (and Heckler). Heath, BTW I just checked mine and I have the same deal as far as the lights on the control unit.....the middle row is out (where the AC and Auto buttons are) and the top and bottom rows do light up.

Well, here is my update. I tried to take IdahoDoug's advice and try an auto electric shop. There was only one in the phone book and when we tried them we were told "we don't work on Lexus".

I tried disconnecting the battery tonight to reset the computer, hoping it would "reboot" after the short from the water. No dice. Too bad, that would have been a great cheap fix.

Signs are still pointing to the control head and AC amplifier, I will post more....hoping to get it resolved soon.

 

[Rich]

What happened to the shop replacing the ac amplifier at no charge?

 

[Seumas]

I went through some AC problems lately as well, the same situation as Reffug actually.

In the process of trying to diagnose (and praying it wouldn't be the same problem described by Reffug), I took the control unit off my 97 FZJ and swapped it with my friend's 97 FZJ 40th.

Some buttons still work but others do not and some other control the wrong things. Basically, the wiring is different. So it might, kinda work but I wouldn't consider it a long term solution.

 

[Walking Eagle]

Did you change the switch in the back from A to M?

 

[Dawnpatrol]

What happened to the shop replacing the ac amplifier at no charge?

I talked with the shop today and got some clarity on that. Apparently the AC amplifier (which also contains the computer, right?) is a more expensive part than the control head unit. So, he says he will charge me the price for the control head unit. I am hoping it is just the AC amplifier and that my control head unit is OK.....

Part is backordered, he says he put it on "emergency order" and hoping it will be in Thurs or Friday, and hoping to get it fixed on Sat. am.......

 

[Darwood]

I talked with the shop today and got some clarity on that. Apparently the AC amplifier (which also contains the computer, right?) is a more expensive part than the control head unit. So, he says he will charge me the price for the control head unit. I am hoping it is just the AC amplifier and that my control head unit is OK.....

Part is backordered, he says he put it on "emergency order" and hoping it will be in Thurs or Friday, and hoping to get it fixed on Sat. am.......

Also make sure you get your windsheild resealed. I'm betting this is where your water is coming from that took out the amplifier.

 

[YngTLCOwner]

Just wondering if what ever happen with this issue?

TTT

 

[Dawnpatrol]

OK, 8 months later - I am super slack for not posting the results much earlier, but now that it's hot again in most of the US.....

My story ends fairly simply, but expensively. The dealer installed the new control head (correct part which includes "Auto" button, apparently specific to LX450's and Anniversary LC's only, right?). It fixed the problem and I've had no AC problems since. I suppose the water shorted out the control head last summer.

I went the new part and dealer route b/c my wife drives the LX as her primary vehicle and I didn't want to go with a used part, only to have it fail the following summer or something. If it was just me driving it.......def. go the used part route. Hope this helps someone, thanks all for the help last year!

 

[IdahoDoug]

Don't miss the message above about your windshield. The 80s w/s must be mounted correctly, which takes probably about 7 minutes more for the w/s installer guys and another $5 worth of glue. They'll routinely blow it off, even telling you "it doesn't HAVE to be installed that way....." Do a search here on leaking w/s and you'll get the message. You have a leaking windshield seal and it's going to fry your new controller.

DougM