Fw: LT-1

[Len Sabatine]

   The LT1 PCM s are not forgiving  in this area. When AC is Fully 
operational , PCM is watching the AC
   line pressure status and coolant temp . Any attempt to run 2nd and 3rd 
fans manually , likely will set a DTC.
   I would think , a hard wired approach , so the PCM can't see what your 
doing may be the only work around.
   Also there is a thermocouple device inserted in the Heater Core for 
additional monitoring , for heating
   and defrost mixing temp control , which is using the AC compressor as 
balance / blend.
   This is a simplistic explanation of the HVAC in LT1 s. The introduction 
of R134A  refrigerant also ushered in
   additional complexity into the systems. In a Hot Rod  , might be easier 
to install an Independent fan with
   a temp delay  when AC is enabled. Just my 2/c.
    Len
>
>Any one able to help here?.
>The PCM is being used in a vintage hotrod, and I haven't a clue about what 
>parameters  the pcm is looking for, and any help on the DTCs or info in 
>general appreciated
>Bruce
>
>I want the pcm to turn on the cooling fan when the A/C compressor is on, 
>to draw air through the condensor.
>If I put and power to the A/C inputs to the PCM eg: A/C request, clutch 
>status, I get DTC,s.
>It would be really nice if I could get someone to turn off the DTC flags 
>for the A/C stuff.
>I need some insight about the 94 -95 Lt-1 PCm's # 16188051.
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