A/C Problem - blowing hot air

H

HelKennedy

New LVC Member
Joined
Dec 27, 2012
Messages
3
Reaction score
0
Location
Pittsburgh Area
This problem is apparently common, but I haven't seen any scenarios that are specifically what mine is doing. My LS is a 2001 v8.

The A/C technically works, but it only blows through the dash vents on passenger and driver side, and it's mixed with hot air. When I put my hand in front of the center dash vent, it feels like cold nice air is blowing through the top 2/3 of the vent, but hot air is blowing through the bottom. All other vents blow hot air, and it gets worse at highway speeds. After extended periods of driving, the air gets so hot it cancels out any cold air through the dash vents (I started to get a burn on my legs one 90F day).

Because what of the cold air that blows is legit cold, I don't think it's related to the A/C system itself, but my heater worked in the winter. I didn't have a problem with cold air being mixed with heated air.

One source describing a similar scenario said it might be due to a fuse - unfortunately, all mine are intact. lol I could wish the problem was that simple.

What am I looking forward to, as far as getting it fixed?
 
Actually, this sounds like exactly the same problem almost every other LS user has faced.

DCCV. Feel free to research. That will be the only recommendation you get until you clearly prove that is not the culprit.
 
There is no top/bottom split on the vents. Still sounds like the DCCV to me.

Joe???????
 
Yes, it can only alter temperature left and right, not top and bottom.
If the air isn't really being heated, but is just not cooled, it could be that they are low on R-134a. It could also be a combination of a failing DCCV and low refrigerant.
 
HelKennedy said:
I got actuator codes, actually.
Click to expand...

Actually, those are not unusual to find on correctly working systems. Were any of them live codes, or were they all memory codes? Clear them and see what comes back over a few days. The actuators only control where the air goes and where it comes from (fresh or recycle). They do not control temperature, with the exception of the cold-air bypass door (gen I only feature). The bypass door does not control temperature other then when it is in the bypass position you get cold air only. In the normal position, you get cold, cool, warm, or hot air as needed. It only goes to the bypass position when you need maximum cooling.
 
Maybe a slight thread hijack.....my system has lately started to intermittantly blow "not cooled" air. maybe only 30 seconds. Can't recall if it occurs when stopped at a light, but I am fearing a AC leak somewhere. I hear what sounds like the compressor or system pressuring up in the car. DCCV was changed 18 months ago. Degas was changed 6 weeks ago. Radiator changed 3 months ago. I am suspecting that the mechanic somehow developed a leak in my refrigerant system. I likely need to get a pressure check of teh system to see if it is leaking or is low on refrigerant.
Secondly, my system may blow cool air out of some vents and I occasionally have to hit a different vent direction to get it to come out the front. Maybe a failing AC control panel?
 
You are hearing the refrigerant flowing past the expansion valve. So far, my experience is that when they make that sound, the refrigerant is one or more cans low. It is normal to have to add some every five or six years. More often than that, and you have a leak to fix.
You may have a problem with one or more of the air door servos (actuators).
 
I'd start with an A/C recharge (with dye) that will probably get you cool again and will help you pinpoint your leak.
 
Got a doosie since A/C posts are coming around. Today i decided to drop the car back down without removing the stands all the way (this is why people say don't rush). I clipped my condensor and before I could stop the jack and get it back up I pierced it - I'll tell you now that that's not a fun experience. Luckily, I was in my garage so neighbors wouldn't freak out, but I did about piss myself

Since I have to replace the condensor now (free recovery charge;) ) I can look into fixing my other issue. Spoke with joegr on this but I want to confirm. I was getting a hi low side and low hi side reading this year and the A/C would get warmer when idling, but on the throttle it was ice cold. I bought a fleebay compressor because I was too cheap last year, and did the A/C myself. I'm about to order a new compressor, but before I do, are those readings consistant with a failing compressor? My system was exposed to the atmosphere for awhile so we pulled a vacuum for a long time just to be sure. I just want to make sure it's a comressor issue and not an expansion valve so I don't go through the same thing again.

And, anyone replaced their main components without replacing the expansion valve, would I be alright if I just got the system flushed before doing a vacuum?

I'm not about to pay $800 for someone to replace the valve and I'd rather not do it myself if it's not a likely failure item beings that replacing it would be a few day job at least. Thanks in advanced
 
Way back when my compressor ate it self. It made a HORRIBLE grinding sound for a minute or so and then was quiet. The dealer replaced the compressor, receiver/dryer and condenser under warranty. That was 12 years ago and the A/C has run fine ever since. The expansion valve was NOT replaced.

I would NEVER get a second opinion after Joe. If you don't know by now, you will learn that Joe has forgotten more about the LS than most people have ever learned.
 
LS4me said:
Way back when my compressor ate it self. It made a HORRIBLE grinding sound for a minute or so and then was quiet. The dealer replaced the compressor, receiver/dryer and condenser under warranty. That was 12 years ago and the A/C has run fine ever since. The expansion valve was NOT replaced.

I would NEVER get a second opinion after Joe. If you don't know by now, you will learn that Joe has forgotten more about the LS than most people have ever learned.
Click to expand...

That's good to hear about the valve. I know someone on here did it, or was it the evaporator core? Anyway, I really, really didn't want to have to do it, and all the info you can find online says replace it. Of course, that's part to cover there a$$ for warranties, but I wasn't sure if it was out of necessity too. Now that I know you've been down this road, I'll just get it flushed and call it a day. My guess is the fleabay compressor I got was just a waste of time and money.

And I concur about joe - I think he wrote the factory maintenance manual
 
Tried the search... couldn't come up with same problems as myself... maybe im just an idiot and didn't use right terminology... lol

05 ls V8, Heat and A/C blows out all vents correctly when selected. However my a/c blows hot. Do I have to recharge or is there another issue I should look into.. before I buy some R134...?? I mean its an 05 with 120K should it be do for a recharge? My 98 century had insane cooled A/C and I sold it 120K and bought it 30K never touched it...
 
BigWayner95 said:
Tried the search... couldn't come up with same problems as myself... maybe im just an idiot and didn't use right terminology... lol

05 ls V8, Heat and A/C blows out all vents correctly when selected. However my a/c blows hot. Do I have to recharge or is there another issue I should look into.. before I buy some R134...?? I mean its an 05 with 120K should it be do for a recharge? My 98 century had insane cooled A/C and I sold it 120K and bought it 30K never touched it...
Click to expand...

Is it blowing hot or just uncooled air? Could be a number of things like it being low. Run a DATC self test.
 
The A/C blows what feels like uncooled air. Like Turning a fan on. So Outside temp with my thermostat turned to all the down to 60 degrees. how do I do a DATC test?
 
The DATC module self-test through the front panel display:

can be initiated at any time. Normal operation of the system stops when the self-test is activated.
is entered by pressing the OFF and DEFROST buttons simultaneously and then pressing the AUTO button within 2 seconds. Record all DTCs displayed.
concludes by reporting all on-demand DTCs. Follow the diagnostics procedure given under ACTION in the DTC index for each DTC given.
reports individual on-demand DTCs as 4-digit DTCs (less the alpha character).
will calibrate all the mode doors and check all analog inputs. The DATC module will only report on-demand (hard) faults that occurred while the DATC module was conducting its self-test.
will light all control panel display segments if no faults are detected.
will report individual on-demand DTCs without the °C symbol lit.

To exit the self-test, press the DEFROST button. This will clear all on-demand codes from the DATC module memory. If no button is pushed, DTCs will continue to be displayed.

Upon exit from the self-test the DATC module returns to operational status. The DATC module executes a hard (cold boot) reset which places the DATC system in the OFF mode.

This test can only catch a few of the things that could go wrong. The next step after this for you is to check the refrigerant pressure. No/low pressure indicates a leak that needs to be fixed. Correct pressure indicates a bad clutch, bad relay, or other wiring or sensor problem.

http://deneau.info/ls/s6x~us~en~file=s6xc0003.htm~gen~ref.htm
 
BigWayner95 said:
12 65 was the code that came up... not sure what that means...
Click to expand...

B1265 1265 Cold Air Bypass Door Actuator Circuit Failure Invalid code. Vehicle not equipped with cold air bypass door actuator. Ignore this code and continue diagnostics.

In other words, they removed a feature without changing the software programming. It's not your problem.

Your problem is not something that the self diagnostics can detect. Refrigerant pressure check should probably be the next step.
 
joegr said:
B1265 1265 Cold Air Bypass Door Actuator Circuit Failure Invalid code. Vehicle not equipped with cold air bypass door actuator. Ignore this code and continue diagnostics.

In other words, they removed a feature without changing the software programming. It's not your problem.

Your problem is not something that the self diagnostics can detect. Refrigerant pressure check should probably be the next step.
Click to expand...

From my investigations on the web, the GEN I LS's did have the outside or cold air bypass door. There are drawings for the 2000-2002 models and the actuator is located forward of the center console on the right of the evaporator core.
 
AutumnRed said:
From my investigations on the web, the GEN I LS's did have the outside or cold air bypass door. There are drawings for the 2000-2002 models and the actuator is located forward of the center console on the right of the evaporator core.
Click to expand...

I guess that I don't understand your point... bigwayner95 has an 05 LS, which is a gen II. I did specifically say that his LS doesn't have the cold-air bypass door. I didn't say anything about anyone's gen I. I have mentioned here before that the gen I has the cold-air bypass door.
 
Hey guys,
So I sold my '02 V8 and found a really nice '06 V8.
I just put my radio in from my old LS into my new LS. After putting everything back in the dash, my AC is not working at all; it's blowing hot air out of all the vents, no matter what temperature I put it on. The AC was working just fine earlier today before the install, as it's finally warming up here in NC. Did I ground something out? Any fuse I can check? I'm really stumped on this one...

EDIT: Self test showing:
12 64
12 62
27 98
 
Last edited:
The codes don't really seem to have a pattern to them. Perhaps you don't have both connectors to the DATC well seated?
 
I just pulled everything back out and reconnected, I have BOTH sitting snug in place. I also noticed while doing a second test, that there is very faint static coming from my front drivers side speaker. I checked all connections and they seem fine..might take a second look at them. I even tried unplugging the radio harness while testing the AC and it's still hot.. I'm super stumped
 
Unplugged everything again and then reconnected. Everything looks fine. Re ran the self-test and now I have:
12 42 *New
12 62
12 64
27 98

So confused right now
 
You must log in or register to reply here.

Members online

Total: 280 (members: 1, guests: 279)
Back
Top