A/C freaking out

ssmoparviii

ssmoparviii

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So I just replaced the compressor on my 2006 LS. Now when I go to charge it the clutch engages and it starts and it starts working but the fan doesn't kick into high. Would that just be a relay or something else? The fan does kick into high when the engine temp gets hot enough. Any feed back would be helpful. Looked around on past posts and couldn't find anything.
 
How much refrigerant did you put in?
What is the outdoor temperature there?
What are the high side and low side pressures (with the windows open and blower on high)?

Just turning the AC on does not alter fan speed. Fan speed increases as the high side pressure increases.
 
joegr said:
How much refrigerant did you put in?
What is the outdoor temperature there?
What are the high side and low side pressures (with the windows open and blower on high)?

Just turning the AC on does not alter fan speed. Fan speed increases as the high side pressure increases.
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I only added 24oz since the system was completely empty. It was evacuated down to about 27 inches of vacuum and left on the pump for about an hour. I do know that the ambient temperature was according to WTForcast "Omg. It's so hot. Who the f@#k even needs clothes today" . I will need to check the pressure when I get home today. I didn't know that the fan speed is operated by the high side pressure. I'm thinking that I got a compressor with a bad rebuild.
 
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Yes, bad compressors (more often scroll control valves) do happen. If it cools at 2500 RPM and not a idle, that's probably the issue. The system holds 28 oz of refrigerant and about 7 oz of oil.
27" of vacuum is not nearly enough. Either you have a bad pump, cheap pump, or still have a leak. You'll need to replace the dryer again after this. You need to pull over 29.9" vacuum.
 
joegr said:
Yes, bad compressors (more often scroll control valves) do happen. If it cools at 2500 RPM and not a idle, that's probably the issue. The system holds 28 oz of refrigerant and about 7 oz of oil.
27" of vacuum is not nearly enough. Either you have a bad pump, cheap pump, or still have a leak. You'll need to replace the dryer again after this. You need to pull over 29.9" vacuum.
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29.92 in.-Hg is considered "perfect vacuum" at sea level, I do not think he will get that close living in Phoenix. He may get 28.8 tops, based on elevation.
 
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jmeecer said:
29.92 in.-Hg is considered "perfect vacuum" at sea level, I do not think we will get that close living in Phoenix. He may get 28.8 tops, based on elevation.
Click to expand...
Perhaps. In any event, 27" seems like miles away from being enough to boil the water out.

You really need a micron gauge to be certain. I haven't justified investing in one for myself, so I just make sure the vacuum gauge goes all the way to the stop (somewhere over 29.0") and keep the pump going for at least half an hour.
 
Well we will see what happens just ordered the replacement compressor and picked up another new dryer. My thoughts on not being able to achieve the vacuum is the bad rebuilt compressor or I small leak somewhere else in the system (need to get the leak tester out before I take the compressor out again). Looking at a chart for vacuum and the current elevation of the city I'm in... Phoenix is about 1000 feet above sea level and according to the chart I looked at 28.9" is the most I will be able to get. But I'm sure that most of this vacuum thing revolves around the bad rebuild on the compressor. I will keep you all posted!
 
ssmoparviii said:
Well we will see what happens just ordered the replacement compressor and picked up another new dryer. My thoughts on not being able to achieve the vacuum is the bad rebuilt compressor or I small leak somewhere else in the system (need to get the leak tester out before I take the compressor out again). Looking at a chart for vacuum and the current elevation of the city I'm in... Phoenix is about 1000 feet above sea level and according to the chart I looked at 28.9" is the most I will be able to get. But I'm sure that most of this vacuum thing revolves around the bad rebuild on the compressor. I will keep you all posted!
Click to expand...

I have another small suggestion, when you are finished vacuuming the system. Turn the pump off, but do not disconnect the pump from the system, leave it connected and watch to see if it will hold vacuum. I watch my gauges for a least 15 to 20 minutes before I disconnet the pump from the system. I found a o-ring leaking one time using this method. System would hold vacuum for ten minutes but slower start to drop afterwords. Good luck.
 
jmeecer said:
I have another small suggestion, when you are finished vacuuming the system. Turn the pump off, but do not disconnect the pump from the system, leave it connected and watch to see if it will hold vacuum. I watch my gauges for a least 15 to 20 minutes before I disconnet the pump from the system. I found a o-ring leaking one time using this method. System would hold vacuum for ten minutes but slower start to drop afterwords. Good luck.
Click to expand...

Good idea... thanks
 
Well it finally cooled off enough in the AZ to get outside and replace the compressor and the dryer. Got it to vacuum down to 28 according to my gauges and it held there. Filled it up with 28 oz of 134a and blows cold now... but only when driving, it blows cool when idling. I'm really thinking the cooling fan is my problem at this point. It was blowing at a low speed even when the engine was up to operating temp with the ac off. What controls the fan? Relays sensors that would cause it not to step up to the next speed? And where are they located I can't find any reference to a relay for the cooling fan or a fuse in the owner's manual.
 
The fan is controlled by engine temperature and high side AC pressure and vehicle speed.
What is your high side pressure when idling?
I tried an aftermarket compressor once. It worked while driving, but couldn't build much pressure at low RPM. No pressure, no high fan, no real cooling.
 
I dont remember what it was right off hand. But what would cause it not to kick on to high even with the AC off? The temperature sensor? Yet no codes are being thrown. Where would the sensor be for the high pressure side?
 
Don't shoot the messengers. Check the high-side pressure before throwing parts at it.
As for engine temperature, if the engine isn't nearly overheating, the fan isn't going to go all the way to high. Do note that it is not a low/high or low/medium/high fan. It is fully variable all the way from off to full speed. It will pick a speed that matches load, and stay there till something changes. It's not like some imports where you hear the fan constantly cycling on and off.

With the AC off, even at over 90 outside, the fan usually runs at a fairly low speed to keep the engine cool. With the aftermarket compressor in, it was hard to tell the fan was even running.

The AC pressure sensor is on the high side line between the compressor and the condenser.
The engine temperature sensor in under the intake manifold. If removed, it has to be replaced with a new one. It is a one-time use.
 
So hooked up the gauges again this afternoon and it was about 95 degrees in the garage the low side was at about 40 and the high side was just pass 150. From all I've seen that's right where it should be unless the LS is just a beast of a different nature. Wrong time of year to have cooling problems plus I hate driving my Journey lol
 
ssmoparviii said:
So hooked up the gauges again this afternoon and it was about 95 degrees in the garage the low side was at about 40 and the high side was just pass 150. ...
Click to expand...

160 PSI would be the min for that (95), but typical would be about 180 (range 160 to 200).
The LS is a variable displacement with thermal expansion valve, so it is a little (not a lot) different.
 
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