Auto Temp II

[roadhogg@xxxxxxx]

Mark.  This is my understanding of how the system works.

In the Auto positions, the system will not start until the engine coolant 
reaches about 120F.  There is a temp sensor built into the water control valve 
that is located in the heater hose under the hood, near the firewall and the 
right side of the car.  There are three vacuum lines going to this valve.  You 
can see a picture of it here.
http://www.nybclub.org/m&r/AutoTempDemoModel/image9.htm
This temperature activated vacuum switch turns on the master switch that is 
located on the top of the airbox under the dash.
http://www.nybclub.org/m&r/AutoTempDemoModel/image6.htm
It is the turquoise one on the left in the pic.
If I were to troubleshoot this issue, I would start by bypassing the vacuum 
switch under the hood to see if it is faulty.  I understand these are available 
new.  Then, check the master switch under the dash pad.  Once you confirm that 
these are ok, it is still doesnt work, please let me know, I might be able to 
help further.

----- Original Message -----
From: Mark Blitman <markblitman@xxxxxxxxxxxxx>
Date: Tuesday, December 24, 2002 2:04 pm
Subject: IML: Auto Temp II

> hi gang and merry x-mas to all..has this ever happened to you? i 
> depress the LO or HI-Defrost button on my '74 Imp to get the fan 
> working for a few seconds and then I depress the LO-HI- Auto 
> button and I hear the blend door close(or is it opening?) and then 
> the A/C works normally....
> 
> Otherwise..if i just depress the AUTO button the a/c will come on 
> but with no fan..and if i lift the hood i will see ice on the 
> expansion valve....
> 
> is this weird or what?..i guess i should be thankful its working 
> although it would be interesting to know what it is doing..thanks.
> 
> mark blitman
> '74 Imperial