AC issue

I just replaced my AC evap core and am having an issue. AC only cools when temp is set to "Lo". When raising the thermostat even one degree, AC vent shifts to floor and blows hot air. Steering wheel control does the same thing.

After disassembling and reassembling the entire dash, I'm sure it is possible to have hooked something up incorrectly. Any ideas guys?

 

I have a ton of pics and video, and it was pretty dang tough to get to the evaporator. I will upload more when I get home. My evaporator was indeed leaking and in pretty bad shape. I have a ton of miles on my car so it was kind of expected. Patrick, any idea where this sensor might be?

 

Thanks. That's a good diagram and gives me some hope that it will be a shallow dig. You really have to take your time and make damn sure you get it all hooked back up. Look at this pic.

 

Well Patrick, I removed the lower panel just below the steering wheel and there was a lonely connector dangling all by itself. I just laughed...I'll be damned, there it is.

Had to pop out the drivers side vent by the door, the panel with the start button, the vent next to the shifter, then and also remove the shifter, then pop out the ac room temperature sensor and saw the connection was not terminated. Fished the wire up to the connector, connected, and now, everything works!

If anyone tries to replace the evaporator core and expansion valve, there is a good video to get you started on YouTube. It shows how to disassemble the dashboard. Will posts pics as soon as I can. Just go slow and double check as you go back together. The blower and the box containing the evaporator core and the heater core SEPARATE. I cracked one of the plastic braces trying to move them both out together. If I had used the Toyota manual I would have known that. Nothing that a drill and strategically placed tie wraps can't fix!

Anyway, a successful evaporator core and expansion valve replacement.

Tks Patrick!

 

Here is the evaporator core I pulled out. As you would imagine, my AC now works sooooo much better!!!! I thought I did a pretty good job cleaning my cabin air filter but as I said I have a ton of miles on my car. Just thought I'd post the pic of the core. And by the way, the heater core looked brand new.

 

Any idea what this cost at a Toyota dealership?? Evap core, exp valve, also replaced condenser as it was totally clogged internally. Vac and fill.

 

It would have been nice to have an access panel to get it out, but noooo....you must remove the entire dash to get to the evaporator core.

Under the hood, it's easier to start by removing the hood.....then go ahead and remove the wiper assembly, plastic pieces that cover the wipers, the wiper cowling, disconnect the AC lines (with a special disconnect tool) after refrigerant is evacuated, and the heater core hoses. Flush and blow out ALL the lines well...I used brake cleaner and compressed air. Also make sure your condenser is not clogged internally or externally...flush it also with brake cleaner and blow it out. IF it's heavily restricted, replace it (I had to replace mine). After I recharged my system, the low side went negative when the compressor engaged. WTH....that's when I discovered the condenser was clogged. Today I was logging 44 degrees out of the vent

And yes I added the proper hybrid oil to the system....to the evap core, compressor, and condenser.

 

Odometer reading---475,000....Yes I will make 500,000 if it kills me.

Patrick...I never found my leak either...mine was bad. I was adding a can every few weeks. But, when I removed the evaporator core, I noticed a stream of dye that had trickled down the drain tube. I didn't check there. Maybe I didn't want to look there....lol.

 

I researched using brake cleaner...and seems to be ok. I say ok.....it didn't pertain to electric compresors. After I blew through everything, I left it open for a day just to make sure. It's hot here in South Texas, so I'm pretty sure it all evaporated....hopefully all is ok. So good so far.

 

Outside temperature was around 98 I believe when I had the 44 degree reading.

 

Well they were all out of Olive oil so brake cleaner had to do.

I didnt flush the compressor. I simply drained the old oil out and added new.

 

Patrick.....Here are the pics and videos I made of the removal. This is not instructional media, simply for me to document how things went back. There is a large molded plastic frame that must be removed. You can see it Some pics and video....I didn't really address it. Just maneuver the wires around it out then back into place going back.

Dropbox - Prius Evaperator Core Replacement

Also the first part of this YouTube video shows the first steps in disassembling the dash.