Re: a/c problems

[mpcripps <mpcripps@mediaone.net>]

Hmmm. We need to determine if the fan is coming on when the AC is turned
on before the car heats up and if the compressor is really coming on too. 
So with a helper, start it from cold, open the hood, and flip on the AC.
*IF* you know what the compressor is. If not, *before* you start it,
look for the component that has a pulley on one end and 2 pipes on the
other. (I'm not trying to be condescending or anything, just don't know
your level of familiarity with the business end of the car.)

Does the fan come on? Then *Carefully* without anything hanging from your
body (like a tie, etc) look at the compressor while your helper flips the
switch on and off slowly. The center of the pulley should rotate when the
AC is on and not when it's off. 

The logic... If the fan doesn't run, that's at least one problem.
But if it's the only failure, at highway speeds it should cool off.
In fact, it should be almost unnoticeably (sp?) different.

If the compressor doesn't rotate, most likely, the low pressure
switch is open because of low refrigerant charge. You *might* be
able to fix that yourself using a recharge kit. But then again,
something nasty could be wrong or you could have an open fuse too! 
So check the fuse box for the correct fuse (the position is labeled) 
and inspect it. You have a Bentley manual, right?

What year is your Jetta? Does the sticker under the hood say it has
R-12 or R-134a refrigerant? 

Mike

>I read your response at work and "investigated" on the way home. I think the
>cooling fan is on at the same time as the A/C but it's hard to tell (it
>continued to run when I shut off the car). At higher speeds, it doesn't seem
>to get any cooler.
>The fan (1-2-3-4) was working as normal, except the air was still hot.
>Previously, when i had it set on "4", it seemed to only push out the amount
>of air that it would on "1", but on the way home it seemed to be working
>fine. So basically, it just blows out dry hot air. Any ideas?
>
>I appreciate your help. I just hope I'm not being too vague.
>
>Thanks again,
>Mark
>
>----- Original Message -----
>From: "mpcripps" <mpcripps@mediaone.net>
>To: <jettaglx@igtc.com>
>Sent: Monday, August 06, 2001 10:28 PM
>Subject: Re: a/c problems
>
>
>> Mark,
>>
>> Several things could be wrong. The receiver/dryer doesn't get charged,
>> it does simply what the name implies. The refridgerant runs through it
>> where any moisture is trapped. It has the same stuff in it as the
>> desicant packs you find in the box with electronic goods.
>>
>> If you can hear the compressor kick in, good. Does the [engine] cooling
>> fan come on with A/C? Does the air seem cooler when you're moving
>> along at higher speed? (The compressor is turning at higher RPM and
>> there's a lot of air moving over the condensor [mounted in front of
>> the radiator]).
>>
>> When you say very little air comes out, do you mean the velocity of the
>> airstream coming from the vents, or the temperature of the air?
>> Does the velocity change when you change the blower settings?
>>
>> We can guide you, but will need more info on the symptoms.
>>
>> Mike