A/C Problems. I need some help

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Jun 10, 2007 | 07:32 PM

mohsinic

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A/C Problems. I need some help

I have a '96 A4 2.8L it doesn;t have a low pressure side so we use the high side to charge and i know its not recommended but i think the '96s don;t come with one. The problem is that my A/C compressor turns on and off when I am driving but if i'm in neutral and idle it runs continuously. I thought it might be the A/C switch located on the low pressure line going into the cabin so i changed that but didn't help. Also I was wondering how to flush the A/C system. The A/C is charged but the cooling is not cold enough like when I put it on Low, the air is cold but not cold enough. Also i read that the restrictor might be clogged and I was wondering how to unclog that or clean it and where is it located on a '96 A4. Should i also open the dash and clean out the Evaporator? would that help @ all?

Jun 10, 2007 | 07:54 PM

ChooChooNongNongHead

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I'd just take it to a shop to evacuate / recharge... and "open the dash" is probably

a good 10-12 hr job.

Jun 10, 2007 | 08:10 PM

mohsinic

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Re: I'd just take it to a shop to evacuate / recharge... and "open the dash" is probably

i thought about that but i wantd to see if i could do something about it myself. I still wana know what the "restrictor" is and i could clean it out myself. B/c i think that might be the problem.

Jun 10, 2007 | 08:57 PM

audinutt

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There's no way way you can fully charge the system on the high side without a machine.

The reason your compressor is short cycling when driving is because of the low charge amount.
The system has a low pressure cut-out switch and this prevents the compressor from burning up.
When you rev the motor the compressor is compressing at a higher rate and this lowers the pressure on the suction side (low pressure) This is why the compressor will run continously at idle.

You have a leak if you needed a recharge.
How bad? I don't know.
You can have the shop charge the system and add an ounce of uv dye.

If it leaks out (starts short cycling again) you can inspect it for leaks.

If none are found it's probably the evaporator and that requires the entire dash to be removed.

good luck!

-richard

Jun 11, 2007 | 02:54 AM

4Driver4

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No free lunch for you. If you want it to work, you need to fix it right.

Have a shop charge it with the correct equipment. That should work for a while anyway. You probably have a bad evaporator.

Jun 11, 2007 | 06:07 AM

mohsinic

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Re: There's no way way you can fully charge the system on the high side without a machine.

okay thats fine. I was wondering if anyone knew what the correct pressure should be on the High side when the compressor it off and when the compressor is running? as i just got a pressure gauge. There was a leak where the low pressure connects to the evaporator and it was a bad seal so thats why i changed all the seals. I think i will end up changing out the evaporator this weekend. It was a small leak b/c i did get it charged by a shop and he said that he hooked up the system and ran it for 15 mins and couldn't see a drop in pressure so it wasn't anything big. After fixing the seal i charged it myself thats why i'm tring to figure out what the pressure should be.Can you change the evaporator by taking out the passenger side of the dash or the whole thing is supposed to come out?