Snarky

My '99 Silverado LS, with manual transmission, had problems yesterday. Twice, during 2 separate cold starts (about 0°F), the A/C was stuck in ON position. I couldn't turn it off or cause it to blow warm air. I could turn off cold air by turning off the fan. The only way I was able to reset A/C was to restart the truck. Any thoughts as to what is happening? The first time it happened, after I drove about 10 minutes at 30-60 mph, the engine died (on Interstate). When I tried to restart, it would turn over, but would die again. I had to wait about 10 minutes before it would restart - then no problems. Is this all related to cold temperatures? Can you flood an electronic fuel injected engine? I just filled up the day before, and the gas had 10% ethanol - so I assume gas line freezing isn't a concern.

tech2

99 old body style or 99 new body style. what engine?


to clarify:
-by a/c you mean the a/c compressor or the hvac system?
-the a/c compressor will not cycle off or the temp blend door will not switch from cold to hot?
as long as the temp blend door moves you will get hot air; regardless of what the a/c compressor is doing.


yes, a fuel injected engine can flood.

Snarky

Didn't expect such a quick response. Its a 3-door extended cab, long bed, 4.8L V8, 4x4. Don't know whether it is new or old body style. When I turned the engine on, the A/C dashboard light was ON. Nothing I did short of turning engine off would turn the light OFF. Likewise, all vents were putting out cold air regardless of temperature setting. Driving for 25 minutes (30-70 mph) did not warm things up enough to cause A/C to switch OFF - I had to turn engine off to "reset", and air from vents remained icy. Given that outside air was icy, I couldn't say for certain whether A/C compressor was running - but heater was definitely not coming ON.

Don't know if it means anything, but I have a block heater (dealer installed). I plugged it in overnight, and the next day, despite unusually low temps, truck started fine and A/C wasn't misbehaving.