Hey guys,

It’s been a while since I’ve been here. The sc hasn’t gotten much attention lately as I’ve had a lot of other things to deal with but I’ve run into a little problem.
I hadn’t driven the car in a month or so and last week I needed to make a run to ACE while working on my other car and had to take the SC.

Between the last time I drove it and now the AC has completely stopped blowing cold (never had issues before). Car has 60k miles.
I’ve done a bit of reading on the forums about what it could be but hoping that one of you can see what I can’t.

The Compressor is kicking on but the L line doesn’t get cold, the Freon gauge is showing in the red (don’t add Freon), the AC fuse in the passenger kick panel is good, the AC relay under the hood next to the horn relay is good, the AC pressure switch in front of the radiator appears good (with the car running and AC on, if you unplug it the compressor stops and turns right back on when you plug it back in) and the onboard Climate Controls diagnostic shows no codes.

Obviate the next step is to head to the dealer or AC shop but hoping one of you can think of something I’m missing that I can check before I take it in.

Thanks,

RMH

 

I've had problems in the past with the thermostatic expansion valve in Toyotas. The TXV controls the pressure of the refrigerant as it goes to the evaporator coil. With age, the AC system can accumulate debris which eventually clogs the valve.

Any time the AC system is opened to the atmosphere, beside changing the bad part, it is recommended to evacuate the system, change the dryer, and some even change the condenser, especially if it is integrated with the condenser. This procedure is beyond most DIY mechanics and is best tackled by a reputable AC-only shop, or the dealer (if one is independently wealthy).

 

Lol thanks, looks like I’ll just have to take it somewhere.

 

Sounds like the EXACT same problem I started having with my 2002 SC430. Everything appears to be working (fuse, relays, compressor clutch, etc.), but it is blowing hot air. It used to have the coldest ac of any car I've owned. I let the car sit in my garage for a few months. Then one day it stopped working. It has 125,000 miles. I hooked it up to a manifold to check the pressure. Both low and high sides barely budge even when the compressor clutch engages. After researching this on many sites and speaking with mechanics, everyone seems to have differing opinions. Common suggestions were to replace the compressor, expansion valve, and/or condenser. A Toyota mechanic friend of mine says that the expansion valve is a common problem he sees, but changing it requires taking apart the dashboard and he was reluctant to work on it because it could turn out to be many other parts impacted. It is a small fortune to have a shop do all this work. I was hearing quotes of up to $2,800 parts and labor! I'm no mechanic but I am very handy and have tools so I decided to take on the project of ordering the parts (about $500) and replacing everything myself. I took it to a shop to have them evacuate the system of refrigerant. I just started disassembling everything yesterday and flushing the system. I can tell you, it's a lot of work but it can certainly be done with the help of good videos on youtube and other ClubLexus posts. I should finish the job this weekend so stay tuned and I'll let you know if it works out!

 

Good luck. Any chance that you took pictures along the way?

 

Curious what was the culprit ?

 

Thanks Harold. I finished the A/C job on my SC430 yesterday. It took me working on/off about three days because I have a professional day job, but most of this time was spent educating myself and analyzing (maybe over analyzing) everything I did because I've never messed with such a complex car project. I also needed to run out to stores a few times because I needed some supplies like extra A/C flushing solvent, dyed PAG oil, and seals. The GREAT NEWS - everything seems to work! The A/C is blowing super cold, probably better than it ever has. It's also very quiet. I took a few pictures along the way, but nothing to write an instructional book on how to do it. I will post what I can when I get the next chance. It was a pretty big job and you will need some tools, but now knowing what I know, I would do it all over again! I also own a Lexus ES350 and Toyota Tundra so I feel confident I'm ready for the next A/C failure and repairs will go much smoother. I was probably nervous about a few things - 1) breaking something, 2) adding the wrong capacity of oil and refrigerant, 3) getting the lines cleaned properly, 4) components/parts which I didn't understand. I found that there is good information and resources out there to help build your confidence. For example, I was really concerned about capacity of oil and refrigerant because from what I learned you need strike just the right balance for your A/C to function well. The problem is that I saw lots of conflicting specs on this. Being a newbie, it was just confusing. I looked at videos, called some shops, but everyone had different answers. I ended up calling the support people at Denso and they were extremely helpful, knowing all the capacities for my SC430 and how their parts needed to be treated. Plus they gave me great tips on how to install.
How much did it all cost me? The cost for everything to do the A/C was $700. Considering all of the major parts that I replaced and equipment I now own, I feel it was cheap! Again, the shops wanted to charge anywhere from $1,800 to $2,800. My $700 would barely cover a new compressor!! I replaced the compressor, condenser, and expansion valve, I've created a materials list for anyone looking to do this for the first time. Yes, you need to buy equipment but it's not that much and I can easily resell

Here's the break down:
- Denso 477-0577 Condenser (comes with drier and bag pre-installed) - Amazon $144.40
- Denso 471-1414 A/C Compressor - Amazon $265.78 (2.4 oz of oil is preinstalled)
- Denso 475-0506 Expansion Valve - Amazon $29.47
- Vacuum Pump & Manifold Gauge Set - Amazon $109.99
- A/C flush kit - canister, gauge, hose, air gun - Amazon $36.99 (you will need to use a simple air compressor with this kit to pump air through the lines)
- A/C flushing solvent - AutoZone - $38 (I used a gallon because I wanted to do multiple flushes)
- PAG 46 oil with dye - NAPA - $10 (need to add approx.1.6 oz of oil to the condenser. The total AC system capacity is 4 oz)
- A/C Seals kit for SC430 - NAPA - $19 (don't buy a universal kit. Be sure to order one specifically for the car)
- Radiator coolant (1 gallon) - Amazon, Rock or dealer - $22.50 (drain/refill needed because the radiator needs to be removed to get to the condenser)
- R-134a refrigerant (3 cans) - NAPA - $19.50 (use pure refrigerant - no additives like oil, dyes or other chemicals)

Hope this will be helpful to you and others! Let me know if you have any questions!

 

Nicely done artdev. Congrats! That's a big job!

 

Check the antifreeze in radiator and reservoir. Mine worked after topping off