Re: Fw: LT-1

[Len Sabatine <sabatine@epix.net>]

  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.