AC Issue
03-12-2009, 09:03 AM
#1
AC Issue History, Last fall if the AC was on for a while the air flow from the vents slowly reduced. If I turned the fan up higher or set the mode to max the air flow didn't increase./ I thought maybe the blower motor was getting hot but didn't really by that line of thinking. Yesterday I read someones suggestion to someone elses problem. Low Refridgent was causing the evap to freeze up and block air flow. That sounds more like it.
Heres the update as it always seems to go.
This morning the AC was still on and when I fired the car up it sounded like a single lifter was ticking. Popped the hood and still sounded like it was inside the engine in the front right. Still sounded like a lifter. I got back in the car and and noticed the AC still on. What do you know shut it off sound goes away. Turn it on comes right back.
So
1. I was wondering that if the noise could be related to low refridge and did mechanical damage definitently occur.
2. Does anyone know a good AC guy in Orlando, FL
thanks Ed
Heres the update as it always seems to go.
This morning the AC was still on and when I fired the car up it sounded like a single lifter was ticking. Popped the hood and still sounded like it was inside the engine in the front right. Still sounded like a lifter. I got back in the car and and noticed the AC still on. What do you know shut it off sound goes away. Turn it on comes right back.
So
1. I was wondering that if the noise could be related to low refridge and did mechanical damage definitently occur.
2. Does anyone know a good AC guy in Orlando, FL
thanks Ed
03-12-2009, 04:54 PM
#4
TECH Senior Member
It might just be low, hard to diagnose over the internet. Sometimes you can hear it "crackling" when the evap is freezing over - turning the AC/DEF off and running the fan on the vent setting in hot weather usually thaws it pretty fast. In order to ice up everything sounds like it's still working, just low on refrigerant. Might get away with just a charge and a leak test.
03-12-2009, 07:31 PM
#6
An LS1 F Body cycles off on the high side, not the low side. It might be the cycling switch or it might be low on charge.
And FYI if you want to know if it's icing up park it on a driveway or something, if it's iced up it'll leave a huge puddle as it thaws out.
03-12-2009, 09:45 PM
#7
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If it is not cycling off it will freeze up the evap. And since our compressors are fixed displacement they are giving all they can when they are on unlike a variable displacment compressor.
Even if it is undercharged it should still cycle off. Because once the low side pressure gets low enough the switch should kick it off.
Unplug the connector off of the switch and see what the compressor clutch does. If it kicks off it is the switch. you can take an ohm meter and check the resistance in the cut-off switch.
Hope that helps you out some.
Even if it is undercharged it should still cycle off. Because once the low side pressure gets low enough the switch should kick it off.
Unplug the connector off of the switch and see what the compressor clutch does. If it kicks off it is the switch. you can take an ohm meter and check the resistance in the cut-off switch.
Hope that helps you out some.
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03-13-2009, 08:19 AM
#8
1. He thinks someone twisted the wires together some where to make it run constantly.
2. He checked the pressures and compressor and he said they where good and the compressor is fine.
3. He said the cooling fans operated properly and the A/C was controlling them as they should. (I looked over the wiring sch. in my Helms and I looked at the para. settings for my EFI live. I notice the only control lines all look they must be intact.
a. How could the A/C control the cooling fans correctly but not shut off the comp.
1) the High side pressure sensor is used to control the fans (must be working)
2) the heat controls turn the A/C off and on (wiring to the clutch must be working){unless cycling isn't accomplihed but the clutch}
b. Pressures and compressor checks out.
c. When manually cycled every 5 or 10 minutes by the driver works great.
I'm beginning to thing its in the PCM!
He offered to have his Tech trace the wiring. (I wasn't to keen on paying for a fishing exposition, especially not convinced it wouldn't turn out ugly for me)
thanks for the input
Ed
2. He checked the pressures and compressor and he said they where good and the compressor is fine.
3. He said the cooling fans operated properly and the A/C was controlling them as they should. (I looked over the wiring sch. in my Helms and I looked at the para. settings for my EFI live. I notice the only control lines all look they must be intact.
a. How could the A/C control the cooling fans correctly but not shut off the comp.
1) the High side pressure sensor is used to control the fans (must be working)
2) the heat controls turn the A/C off and on (wiring to the clutch must be working){unless cycling isn't accomplihed but the clutch}
b. Pressures and compressor checks out.
c. When manually cycled every 5 or 10 minutes by the driver works great.
I'm beginning to thing its in the PCM!
He offered to have his Tech trace the wiring. (I wasn't to keen on paying for a fishing exposition, especially not convinced it wouldn't turn out ugly for me)
thanks for the input
Ed
03-13-2009, 12:35 PM
#9
I wonder how he knows the AC is controlling the fans or the engine coolant temp is controlling them.
Usually if someone jumps the pressure switch, it's right by the switch, which is on the liquid line a few inches past the dipstick.
Also wondering what year car you have.
Usually if someone jumps the pressure switch, it's right by the switch, which is on the liquid line a few inches past the dipstick.
Also wondering what year car you have.
03-13-2009, 01:30 PM
#11
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better find a factory manual and show your ac guy...you don't have a cycling system like was used years ago...your compressor unloads....the comp runs all the time unless certain conditions are present like too low pressure too high , hot rengine start and few other engine codes can turn it off.good luck
03-13-2009, 10:27 PM
#13
03-14-2009, 11:47 AM
#15
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NOOO the compressior itself unloads....get a factory manual or find better mechanics! The pressure switch is there to moniter the system and let the computer know if its safe to turn the compressor on.
03-14-2009, 01:30 PM
#17
This is exactly why the automotive AC forum elsewhere on the internet will not bother answering your questions unless you fill out the form.
Questions like this---- NOOOO.
The mechanic did this and that, well he didn't fix it, what do WE--ls1tech members do? Guess, argue, etc.
The pressure switch monitors the system alright, like I said, it'll count the time between cycles and when cycles become too close it'll lock the compressor off. Among a few other things.
AC problems, I find, are the most frustrating to help with in a forum because NO ONE has the right tools, and those who do have the right tools don't ask questions because they usually know how to use them, and have several times since the cost doesn't justify a one time use.
So getting back to the topic. The mechanic said this and that, doesn't help anyone here. Let someone who knows what they're doing fix it.
03-14-2009, 05:58 PM
#19
Letting an A/C guy fix it was why I went to a place that only does A/C. But when he says he needs to start tracing my wiring hand over hand, starting at the pressure switch that he pointed out to me on the inner fender panel about foot behind the compressor. He had the pressure gages hooked and said he compressor was fine as was the refriderator level. He mentioned the fans were cycling ok as directed by the A/C system. I myself wondered how he knew the A/C ordered and not my ECT. When I got home and pulled out my Helms it became clearer to me that he didn't have the full grasp on the wiring.
Ed
Ed
Last edited by BRD-PREY; 03-14-2009 at 05:59 PM. Reason: spelling
03-14-2009, 06:04 PM
#20
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THE COMPRESSOR DOESN"T CYCLE! geez you are low on charge OR sucked some paper like tissues maybe into the air intake. The compressor UNLOADs...its does cycle like the older GM system. Get over it and move on and get your car fixed by a pro.