2003 Venture A/C I have the pressure readings now?

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brian

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#1
I am posting the pressure readings from my 2003 venture a/c. The low side reading is 104 and the high side reading is 1. I know that this can't be right so any insight would be greatly appreciated. Also the whole time the compressor is not running. With the switch turned on and there is no noise coming from the compressor like you would normally here when you turn it on. Brian
 
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#2
To get the pressure readings you need the compressor running.
75-100 without compressor running sounds about right.
But low and high side should be same.
Your high side gauge is not getting a connection on high side hose coupler.
Sometimes you need the adjustable couplers to tap the pressure readings.

Figure out why compressor is not turning on or how to jumper the compressor with a fused jumper and get it running.
The give us the low and high side readings at idle and AT 2K RPM.
 

Gus

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#4
You have enough pressure to run the compressor on the low side(like Crunch says, I think you have a bad connection on the high side....they should be equal).....

Have checked for codes? Hvac codes will not turn on the CE light, but will disable the compressor circuit......

Could also have a bad A/C CLU fuse, bad clutch relay, bad PCM(rare), or a bad pressure sensor(i.e., if the sensor is reading too low or too high a pressure, when in fact it is normal, the PCM won't ground the A/C clutch relay)....
 
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brian

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#5
I will get the codes checked today. As far as the relays and fuses go in the box they look o.k. and I swapped the micro relay with the one for the horn and that didn't work either. Is there a way to check the pressure switch or is it a case of put it in and hope that it works. I am not sure about the clutch relay if this isn't the one i mentioned above. And what is a pcm. It just started to not get as cold as normal and then quit working all together. Brian
 

Gus

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#6
The main component of this system is the pressure sensor....unlike pressure cycling switches, it can't be jumpered......

As I said before if your pressure is ok(hi and lo), but the the pressure sensor is providing incorrect info to the PCM(computer), the computer will not ground the A/C clutch relay....it also won't ground it if there is an A/C code set or if there is no A/C request from the control head.....the only way to see what the PCM is reading from the pressure sensor is with a scan tool....
 
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brian

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#7
Will the pressure sensor code show up on a regular scan tool? If I take it to Auto Zone or somewhere like that will it show up. The compressor will have to be jumped to get it going because it currently won't turn on and I can't get a pressure reading with out that running correctly. Correct me if I am wrong. I don't know much about a/c systems. Thanks for your input. Brian
 

Gus

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#8
P0530 or P1546......but you also need a scan tool, like i said, to see what the pressure sensor is telling the PCM....too high or too low, will disable the compressor....
 
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Brian

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#9
Re: 2003 Venture A/C ?

It's been awhile but here goes. We took it to a mechanic today and he checked it out. what he told me is he rthinks there is something wrong in the computer. he checked the voltage before and after the computer and the switch in the van is sending the voltage to the computer but there is nothing coming to the pressure switch. He also checked the refrigerant level and said that it is o.k. is there a wayy to reset the computer other than disconnecting the battery. I am going to give this a try as he didn't and said what could it hurt. It probably won't fix it but it is worth a shot. Any insight would be great. Brian
 

Gus

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#10
OK, you took it to a mechanic....now bring it to a tech who knows what he is doing....

Was there a code? Did he read the data in the computer from the pressure sensor? Did he check for an "A/C Request"?

How in the world can you check refrigerant level, if the system doesn't run? By reading pressure? Reading pressures doesn't tell you what the freon level is......this isn't brain surgery, it's a simple system with the right tools...
 
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brian

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#11
turns out the first guy was right. maybe he is more of a tech than a mechanic. I took it to the dealership where they hooked it up to a scan tool and told my wife it was the high pressure sensor. They then told her with a sensor, cabin filter and vacuum and refill of the system it would be $500 and change. She laughed. I called back to the dealership and asked if the tech had bothered to check the sensor for 5 volts. He said no but if I brought the van back they would check it out. Well upon further review they told me it had no voltage at the sensor and that I should check the wiring harness. I looked and found a broken lead about 2 inches off the sensor. Guess the first guy was right after all. The air is cold and blows alot of cold, cold air. fixed