31240Re: [classicrv] Re: Chevy AC questions - G30
- Sep 1, 2008John,
Just to muddy up the waters some more. . . . Most GM's, and I suspect other brands as well, will run the AC if the heater is set to defrost or defog. That forces the warm air for the defroster/defogger to pass over the AC cooling coils as well as the heater coils for the purpose of dehumidifying the defroster/defogger air and preventing water from forming on the interior sides of the windows.
--- On Mon, 9/1/08, John <jgra1@...> wrote:
From: John <jgra1@...>
Subject: [classicrv] Re: Chevy AC questions - G30
Date: Monday, September 1, 2008, 3:45 PM
ok made some progress ;)
basically.. if a flap in the heater core is in a certain position,
power will flow to the cold air fan and also the AC temp knob..
I am guessing this is to recirc air so as not to waste [gain]
energy... or simply to 'ban' cold air if warm is also asked for first...
if I by pass this flap and it's dodgy? contact, and send a current
straight to the destination, I can get the cold air blower off /1 and
2, if I connect the burn't out wire i get 3 too :)
so I have 3 speeds on heater blower and three speeds on cold blower.
If I then turn the AC cooling knob on, the AC clutch engages, and
presumably if the engine ran, I may even have AC :)
two more things..
the current that is allowed to pass to AC if the flap is closed - the
flap seems to be partly vacumn operated... I am guessing you can't
have cold air blower going until the engine has warmed up...o9r something
also, the same wire from the heater core goes into yet another vac
swtich, before it is allowed onwards to AC and cold air.. maybe you
have to have engine running before cold air and ac allowed... i.e a
anyway, I dont care :) I am much happier now.. I understand the
heating and cooling much better already..
ps shame summer is over ! lol
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