Date: Mon, 27 Jul 1998 07:33:29 -0400
Reply-To: EMZ <vw4x4@FYI.NET>
Sender: Vanagon Mailing List <Vanagon@vanagon.com>
From: EMZ <vw4x4@FYI.NET>
Subject: Re: A/C Freezing Up?
In-Reply-To: <199807270755.CAA07865@riptide.wavetech.net>
Content-Type: TEXT/PLAIN; charset=US-ASCII
Your AC control unit is working over time. It is the little
black box on the C-piller. It is nothing more than a relay that
is controlled by the dial on the dash, (a variable resistor) and
a thermistor located in the evaporator. This system works great
when working, but expensive the fix. You can by pass it by using
a switch in place of the relay contacts. Been there done that.
Eric 86-VW4x4
vw4x4@fyi.net 72-240z
Pittsburgh, PA USA 1936-Chrysler
On Mon, 27 Jul 1998, Budd Premack wrote:
> The a/c on my 86 Syncro GL (non-Westy) was inoperative when I purchased it
> two years ago. Two weeks ago it was reborn with several hose repairs, a
> new receiver dryer and an infusion of 134A refrigerant and special ester
> (sp?) oil. It works great, but....
>
> With the temp control knob on the warmest setting, the air is really cold,
> and does not feel any colder if the knob is turned to a "colder" setting.
> (Sorry, I have not checked it with an accurate thermometer.) After about
> 45-60 minutes the air gets warmer until it seems as if the a/c is no longer
> operating. If the van is parked for 30-60 minutes, there is a puddle under
> the right side of the rear bumper (water from the drain hose). Upon
> restarting, the a/c works fine again. I have not had the opportunity to
> run it through several consecutive on and off 60 minute cycles as I have
> not had any all day trips this past two weeks. It does seem as if there is
> a longer period of proper operation if the humidity is lower and/or the
> ambient air temperature is lower. Naturally, these conditions would put
> less demand upon the a/c system. On a nightime 90 minute drive at 75 F
> ambient, the a/c was so cold, even at the lowest fan and temp setting, that
> we mostly closed the front a/c air vents. This was with only two front
> seat occupants, and the rear vents all closed.
>
> Note to all of you sweltering down South: I am not complaining about being
> too cool, just making a statement to aid in problem diagnosis. Besides,
> you don't really want to trade your winters for those in Minnesota.
>
> It seems to me that the system may be running at maximum cold capacity and
> then freezing up. What is the problem? Is it a bad temperature control
> switch, a/c thermostadt or capillary tube, expansion valve, or ? The top
> and side pillar housings were not removed, so the evaporator, expansion
> valve, relays, etc. have not been physically examined.
>
> All suggestions will be shared with my ace mechanic, who seems quite
> capable with a/c systems and Vanagons. (He went on vacation after fixing
> my a/c, but will be back soon.)
>
> Thanks in advance.
>
>
> Budd Premack
> 86 Syncro, 73 Super
> Minneapolis, MN (Land of Sky-Blue Waters)
>
|