Windstart AC woe's, need help.

[Aldures]

Hello all,

I have had no AC for over a year now on my windstar and decided I have had enough of the heat. I started looking into the problem and reading the message boards here and this is what I have found so far.

1.There was no freon or very little left in the unit when I tried filling it.
2.As I was trying to fill the unit the compressor would turn on and off, cycling every 5-10 seconds all the time and I wasn't able to fill the unit up.
3.No cold pipes on the left side of the motor where the ac is when ac is on.


I haven't ruled out a leak but I am guessing I have a problem with a low pressure valve. Would this be a correct assumption? If it is a valve what is it called and where is it? I noticed a few wires connected to a pipe on the ac (front side). Is this the so called low pressure valve I hear everyone talk about?

Thanks in advance,
Tim

[CDJr]

Im guessing your assumption is wrong. The low pressure switch is probably doing its job by cutting the compressor off every few secs. That keeps the compressor from running for more than a few secs when low on refrigerant, to stop it from burning up. If it has very little or no freon, then its a pretty bad leak, which is good and bad...bad, for obvious reasons, and good, cuz its usually easy to find. Look for oily spots around the connections, especially on the high pressure lines, as theyre more prone to leak. Somtimes a few simple O-rings will remedy the problem.
As far as charging it, you can jump out the low pressure switch which forces the compressor to run, but only do this while charging it.

[Aldures]

Originally Posted by Aldures

Hello all,

I have had no AC for over a year now on my windstar and decided I have had enough of the heat. I started looking into the problem and reading the message boards here and this is what I have found so far.

1.There was no freon or very little left in the unit when I tried filling it.
2.As I was trying to fill the unit the compressor would turn on and off, cycling every 5-10 seconds all the time and I wasn't able to fill the unit up.
3.No cold pipes on the left side of the motor where the ac is when ac is on.


I haven't ruled out a leak but I am guessing I have a problem with a low pressure valve. Would this be a correct assumption? If it is a valve what is it called and where is it? I noticed a few wires connected to a pipe on the ac (front side). Is this the so called low pressure valve I hear everyone talk about?

Thanks in advance,
Tim

I really don't know much about cars and even less about ac so your input is really valuable!

I am thinking that I should probably bring this to a garage and get it fixed since I don't know what I am looking for. I can give it another go tonight and check for oily connections but I didn't notice anything. That's probably my own stupid fault for keeping the engine compartment clean...<sigh>

There is one thing I forgot to mention. I noticed before the ac stopped working a year ago that when the ac was on there was a hissing sound akin to an air leak sound behind the climate control inside the vehical. Last night when coming back from tinkering on the van I was hearing the same sound again. My question is could the leak be inside the van and has anyone else ever heard this hissing sound when the ac is on? IT could very well be normal and I never noticed it before.

Once again thanks for any and all help!!!
Tim

[floridatgp]

I always put the can of freon in warm water to get the pressure to rise and speed up the deliver to system, if the low preassure switch is cycling, that is a good sign you compressor is pulling freon, my friends car AC was not even cool, just one can later, cooling good. Just get more freon in the system before you give up.

[CDJr]

Ummm, as far as the hissing sound goes, thats probably not the leak, as the system is under constant pressure whether its turned on or not, but anythings possible. So it would hiss always. You might go ahead and put in the freon you have...just jump out the low-pressure switch to charge it up. Then after you get it all in there, you can turn the system off and listen for leaks and maybe find it that way.

[Aldures]

Originally Posted by CDJr

Ummm, as far as the hissing sound goes, thats probably not the leak, as the system is under constant pressure whether its turned on or not, but anythings possible. So it would hiss always. You might go ahead and put in the freon you have...just jump out the low-pressure switch to charge it up. Then after you get it all in there, you can turn the system off and listen for leaks and maybe find it that way.

Thanks for all the usefull info!!!! I have been busy for the last two days but I will try and give this a try in the next couple of days. I will post up my results the minute I get some.

Thanks again for all the info, you guys are a God send for the mechanically inept hehehe.

Laters and have a great weekend!

Tim

[Aldures]

Originally Posted by CDJr

Im guessing your assumption is wrong. The low pressure switch is probably doing its job by cutting the compressor off every few secs. That keeps the compressor from running for more than a few secs when low on refrigerant, to stop it from burning up. If it has very little or no freon, then its a pretty bad leak, which is good and bad...bad, for obvious reasons, and good, cuz its usually easy to find. Look for oily spots around the connections, especially on the high pressure lines, as theyre more prone to leak. Somtimes a few simple O-rings will remedy the problem.
As far as charging it, you can jump out the low pressure switch which forces the compressor to run, but only do this while charging it.

I do have one small question, where is that low pressure switch I have to jump and how do I jump it? Do I remove the wires and apply 12 volts to the terminals? If yes which terminals? I know I know, lots of questions, but I don't want to break anything.

Thanks in advance.
Tim

[hupkwondo]

Originally Posted by Aldures

I do have one small question, where is that low pressure switch I have to jump and how do I jump it? Do I remove the wires and apply 12 volts to the terminals? If yes which terminals? I know I know, lots of questions, but I don't want to break anything.

Thanks in advance.
Tim

First of all, I wouldn't fool with jumping the low pressure switch - that is there for a reason, namely to protect your compressor.

Secondly, there usually isn't an oily residue surrounding a leak in system susing R-134 - a different lubricant is used in these systems and the new ones tend to evaporate before they can stain anything.

Thirdly, you've got a leak. You could keep putting freon in it and it might even work for a while, like an hour, but it will stop working pretty quickly.

Check your under hood label and make sure you're using R-134. Almost every car made after 1995 or so will use R-134. Only older cars use the R-12.

If you're using R-134, here's an easy check. Go to Wal-Mart and get the can of freon that has a gauge attached to it. Make sure you get the gauge - that's critical to this check. It will cost you about $20 or so. Follow the instructions on the can and connect the can to the fitting under the hood with the a/c and engine off and observe the reading on the gauge. On a fully charged system, the reading will be about 100 psi (well into the red on the gauge). Start the engine and the a/c - the reading should drop below 40 psi. This indicates the compressor is working and sucking freon from the low side and pumping up the high side. You can keep adding freon (by pressing on the dispensing button) until the gauge reads 40 or so. You should also be getting cold air.

If this works, all of the pieces of your a/c system are functioning as they should - usually one can is enough to get cold air. If you're really empty, you might need two.

Now, if the cold air comes out for a while but tomorrow its not working agin, you've got a leak. If your van is over 8 years old or so, its PROBABLY the compressor. If you're really handy, you can detect and fix the leak yourself, but you will need a vacuum pump to evacuate the system after fixing the leak. If you don't have a vacuum pump and a set of manifold gauges, its time to take it to the shop and let an experienced mechanic fix it.

Good Luck.