it could be a few things, but id check the thermostat as its probly stuck open, or your heater core could be bad but that will cause a water leak in your car and its a pain to change. or you can check your heater hoses for sludge.. because 50/50 anti freeze tends to cause that
thermostat stuck open or air in cooling system
my heater fan in front of my 2004 chevy venture van wont work
i dont have no power to my starter solinode wont start its a 1985 camero
Check your coolant. Is it thick and gunky?
Something is wrong with your 2000 Chevy Venture. Better information get's better answers.
check heater fan to see if it is working.
Likely heater core. I had same problem with 1996 S-10 with 4.3L.
fan motor could be bad
Because it hates you!
I've got a better question, why is this question in the Chevy venture forum ?
A blockage in the heater core is the most likely cause. This is a difficult and expensive repair.
try the bend door