Date: Sat, 3 Aug 2002 11:00:04 -0500
Reply-To: Larry Alofs <lalofs@ENTERACT.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Larry Alofs <lalofs@ENTERACT.COM>
Subject: Re: Air conditioning electrical questions
Content-Type: text/plain; charset=us-ascii
Rob Scott wrote:
>
> The patient: 1990 Westie MV, US model
>
> I had my air conditioning system evacuated (R-12 removed) and leak tested
> today. Very slight leakage in the system, but not enough to prevent me from
> filling it with dye charged ES-12 and using it for the rest of the summer.
> I am having some problems charging the system and I'd like to ask some
> advice from the experts assembled.
>
> It's currently quite cool here near Seattle. The thermometer was reading
> in the mid-sixties when I started work in the late afternoon and it's easily
> down near fifty at the moment. While attempting to charge the system, I
> tried to turn on the system to run the compressor and suck the refrigerant
> into the system. The AC fans are running, but the compressor is not kicking
> on. Anyone think that the cool temps may be keeping the compressor from
> running? There is both an outside temp sensor and an evaporator temp
> sensor, either of which may be reading too cold for the compressor to
> kick on (the external temp sensor isn't supposed to block this unless it's
> a lot colder than this, though).
>
> Is there any way to force the compressor relay to kick on? Anyone have
> any recommendations as to which of the wires on the compressor to check
> to see if I'm getting current to the compressor (this would at least
> eliminate the possibility of the compressor being seized).
>
> Anyone have any reputable wiring diagrams for the AC system? The Bentley
> doesn't cover the AC system on the wiring diagrams (at least not that I
> can find). Having a wiring diagram may help me figure out how to
> troubleshoot this.
>
> Thanks in advance. Cheers.
> Rob
>
> It's never too late to have a happy childhood.
> -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
> Rob Scott, mailto:rob@unixguy.com
> Langley, Washington on Whidbey Island (a suburb with a moat)
In my Bentley the AC info is section 87. 87.6 shows some useful
pictures but no actual circuit diagram. In particular note the low
pressure switch. If there isn't enough pressure in the system, it
disables the compressor. The idea is that the compressor will be
damaged if there is no refrigerant to move the oil around. Assuming
that you are charging into a vacuum, this switch should prevent the
compressor from running.
The instructions on my cans of ES-12 say to put in one can BEFORE
starting the engine. If you're using a gauge set (recommended) you will
be able to tell if this gets the pressure above the 43 psi expected by
the low pressure switch.
In my GL the low and high pressure switches are behind the plastic
cover at the left rear (D) pillar. I don't know about Westies, but I
suspect they may be in or behind a closet. I believe that in the latest
models the two switches may have been combined into one assembly.
good luck, let us know how it turns out.
Larry A.
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