Need an A/C guru

jsukey said:
Okay guys, time for an update. I've been at work all day, and couldn't put hands on the 4Runner. When I left work at 6, I started it up and was just curious to see if it would kick on. What do ya know...freezing cold air! That tells me that the expansion valve is intermittently hanging. I couldn't get in touch with my buddy, so I stopped by autozone to rent a set of gauges. Of course they were all out on loan. I will update with more info when I have a chance to put some gauges on it. Work is pretty busy right now. I'm certainly not looking forward to tearing out then entire evaporator to replace the valve and drier. Does anyone have any pointers to tearing it out?
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I've been researching it but I haven't done it yet. Hoping current charge gets me through the summer. The FSM has info. You can pull the cooler as a unit after pulling the glove box and breaking the pipe connections on the engine side of the firewall. Not near as bad as some cars where you need to pull the whole damn dash.
 
It is close to replacing one on a Camry as per SK:
https://www.youtube.com/watch?v=RkKry31lk1E

I can't remember the two wrench sizes to loosen the nuts for the lines. 21mm, maybe 22mm.

Unlike SK, I would replace the drier as well located in the front.

I am thinking fellow members [MENTION=25434]BamaDrewski[/MENTION] and [MENTION=149260]habenero[/MENTION] both have replaced theirs in the past. Possibly PM them for more insight.
 
On a 3rd Gen you don't need to tear into the dash to replace the evap and/or the expansion valve. Pull the glove box and everything is accessible from below. It's an easy job compared to most other vehicles and the cost of a new evap and expansion valve is reasonable on Amazon.
 
I was browsing some A/C threads and I happened on a thread from 2014 where a helpful poster had uploaded the A/C diagnostics chapter from the FSM to this site as an attachment, so the link still works.

Imagine my surprise to see the helpful poster was me.

Here is the link:

http://www.toyota-4runner.org/attachments/3rd-gen-t4rs/123924d1404335562-hot-ac-recharge-ovi.pdf

Here is the thread with some good stuff.

http://www.toyota-4runner.org/3rd-gen-t4rs/172671-hot-ac-recharge.html

I talk about the first DIY evac and fill I did on my son's e36 in the summer of 2013. Said BMW is still blowing cold right now in 2017. No issues since then.
 
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The AC system started acting up on my 96 a while back, stumped me and certified mechanic both with several years AC experience.
PSA
My filter/drier desicant cartridge disintegrated into 1000's of pieces totally wrecking AC system: $1600.00 later it worked. CHANGE THE FILTER/DRIER
thats something I can't emphethize enough!!
 
I still haven't had a chance to hook it up to the gauges. It performed flawlessly last night and this morning on the way to work though. I plan on changing the expansion valve and the drier together. I promise to document and photograph the entire process though! I can't really complain though...I'm sitting at 267,000 miles and this is the first A/C problem that it's had according to the records and my history with it.

The system hasn't been open, other than recovering the refrigerant and replacing the hi/low switch. The switch was done within seconds though. It would freeze you out before, and after that change. Whenever it's acting up though, the compressor hub is not turning. Perhaps it is just the drier?! Either way, I'm going to go ahead and replace them both. It's 17 years old, and I would really like it done right so I no longer have to worry about it.

I have the digital controls, so nothing could have popped off for the heater.

96RedRunner said:
The AC system started acting up on my 96 a while back, stumped me and certified mechanic both with several years AC experience.
PSA
My filter/drier desicant cartridge disintegrated into 1000's of pieces totally wrecking AC system: $1600.00 later it worked. CHANGE THE FILTER/DRIER
thats something I can't emphethize enough!!
Click to expand...
 
Anyone looking to get this done as well should check out RockAuto for the parts. They sent me a 5% discount this morning. With shipping and both parts, the total came to $34.85 for both parts. Those are OEM Denso parts as well.
 
Have you checked for power at the clutch when it should be running? Digital controls to me get flakey with age and add another element to what's wrong. If your shutting off on high pressure the compressor should still cycle on and off just like if it was low on charge and shutting off when suction pressure goes below 25psi (as an example)


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I haven't. But the first time it acted up, I jumped the harness at the hi/low switch and it immediately kicked on and started cooling correctly. It didn't work the second time though. I was thinking that maybe the compressor couldn't overcome the pressure created by the sticking of the expansion valve. That's just a guesstimate though. I thought that perhaps the expansion valve was only sticking intermittently. I didn't have gauges to check the high and low side. I work about 2 1/2 hours away from home, so I'm limited as to what I can do. Went by Autozone yesterday to rent a set of their gauges, but they had already rented them out.

19963.4lsr5 said:
Have you checked for power at the clutch when it should be running? Digital controls to me get flakey with age and add another element to what's wrong. If your shutting off on high pressure the compressor should still cycle on and off just like if it was low on charge and shutting off when suction pressure goes below 25psi (as an example)


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Click to expand...
 
jsukey said:
Anyone looking to get this done as well should check out RockAuto for the parts. They sent me a 5% discount this morning. With shipping and both parts, the total came to $34.85 for both parts. Those are OEM Denso parts as well.
Click to expand...

You may as well change the evaporator while you have the system opened up. They don't cost all that much and old ones are almost guaranteed to develop a leak sooner or later.
 
Okay, let's see what this turns up! So I ran the diagnostic on my climate control. It flashed a 21 at me for the solar sensor circuit. I remember having a problem with the same climate control module in my '02 over 10 years ago. The temperature wouldn't climb when I turned the knob. The dealer replaced it under warranty. I haven't noticed any issues with this control module. Could that be the issue to all of this?! I read about an eBay merchant that repaired them for $100. Is it my module, or the solar sensor though?

Edit: Make that $47.50 plus the cost of shipping it to him. He has 100's of positive feedback about the repair, and 1 negative. That person thought they were buying the module instead of the repair.
 
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Okay, disregard all of the wacky climate control diagnostic stuff. I did more research and just discovered that it will always throw that code if there is no sunlight on that solar switch. I had my window shades on earlier. I just tested it with and without them and it cleared the code immediately. Looks like I'll be doing all 3 components. Evaporator, expansion valve, and drier. Around $140 total in parts for OE Denso. I will post back.
 
My brother's friend had a wacky climate control with no codes but would not allow his heat to be controlled at the unit unless turned to HOT first, then turned down. Turned out some solder joints were toast on the board.
 
jsukey said:
Okay, disregard all of the wacky climate control diagnostic stuff. I did more research and just discovered that it will always throw that code if there is no sunlight on that solar switch. I had my window shades on earlier. I just tested it with and without them and it cleared the code immediately. Looks like I'll be doing all 3 components. Evaporator, expansion valve, and drier. Around $140 total in parts for OE Denso. I will post back.
Click to expand...



Does the FSM mention sunlight? Or the solar switch theory of operation?


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I read it from a post that popped up on Toyota Nation after searching Google. Didn't have any luck here. This was his post:
-

The Solar Sensor is on the left top side of dash(with a dome over it). It does NOT come out easy. There is not much room, and the two clips holding it in are directly in the front, and directly in the back. I worked getting two out of wreckers to try in my situation. Before you go through that trouble- make sure you are in the sun and the sensor is in the sun, and THEN run the test. U may find it works fine.

-
I tried it with the shade in place and it popped the code. I moved the shade and it immediately cleared the code.
 
Wonder if that just a simple inferred sensor. The odd part about his post is that it would always code when it gets dark outside. It could also be RTD or thermocouple. The Grand Cherokee I have would have had a inferred sensor for climate control had it not been the manual climate controls.


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I have the infared sensor on my 2010 Jeep SRT8 climate control as well. I don't know what the differences are. Never had to deal with this kind of issue before.
 
Finally got the problem to recreate itself after driving 150 mikes straight. I pulled over immediately when it stopped blowing cold air. All of the underhood lines were hot, so I don't think is a freezing issue from moisture in the system. I could still see water dripping from the evap core. Really leaning towards the expansion valve. I drove to the closest Autozone and rented their gauges. Here is what they showed with the engine running, A/C on high, and the compressor not engaged.
 

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