My 1997 Silverado seems to have the A/C running all the time, when I turn off the truck I notice that the system would make a hissing sound like it was releasing air pressure. I wanted to know if this normal operation for this year of truck?

I am not intirelly sure it is the A/C. It could be the fuel line releasing preasure back into the tank. if you have the interior set to defrost, that still uses the A/C compressor.
I had a 93 that would do that too.

Could just be your intake. My 2004 4.3L's intake makes the sucking sound every time I shut it off.


Peace, Gary

[quote=ThorAxe]My 1997 Silverado seems to have the A/C running all the time, when I turn off the truck I notice that the system would make a hissing sound like it was releasing air pressure. I wanted to know if this normal operation for this year of truck?[/quote.

I guess I should have mentioned that I checked under the hood and felt the A/C units and they were cold and sweating.