1993 Sonoma 4.3L V-6 with 55K miles. AC is cold and works well until I come to a traffic light and am stopped for a while. Engine temp registers around 205-210 degrees F here in San Antonio summer weather. I am hoping for a simple fix. Is there a engine temp sensor, or some other electronic part that could be bad or failing? AC was serviced last year and was judged to be in good working order.
AC blows hot and humid at traffic light or at idle in Park
- Thread starter Mel Amick
- Start date
mogleybear
Member
I seem to recall this being an issue with several GM trucks and if I remember right the most common reason for it was the fan clutch, not allowing the fan to pull enough air through the grille to allow the AC to cool while idling. When driving enough air is forced through to help. Something to check anyway.
mogleybear
Member
I don't know if there is a separate sensor for the AC system. Sorry.
Just spit-balling here but if you only notice this when you are stopped with your foot on the brake it might be somehow related to the vacuum system. Perhaps the extra requirement of vacuum for the power brakes might be causing a blend door to open allowing heat to enter the system.
I have not had any experience with this but I could see how a leaking power brake booster could lead to the behavior you describe.
Good Luck!
I have not had any experience with this but I could see how a leaking power brake booster could lead to the behavior you describe.
Good Luck!