You can run a hot wire over to the alternator to the compressor (I think
the hot wire on that is green while I know the ground is brown if there
is one).  This will allow the compressor to come on so you can charge
the system.  I usually don't have this problem however.  I start to
charge the system into both the low and high side ports as much as it
will take.  Then I shut off the high side.  Then I start the van furn on
the a/c and get a small pot of warm water.  I set my can of refrigerant
in this warm water and after a few minutes of charging into the low side
port the compressor will kick in because the pressure is high enough and
then you can finish your charge.  It seems like a reading of around 37
psi on the low side is about right with r134a.

Hope this helps,
Ken Wilford
John 3:16
www.vanagain.com

Chris Snyder wrote:
> >From what list members have told me, I need to bypass the A/C low pressure
> switch to get the compressor to run so I can recharge the system.
>
> What or how do I bypass this switch?
>
> Thanks in advance
>
> Chris S.   </HTML>
>
>