92 corsica no very little vent heat

My 92 corsica does not blow warm air out of the vents at idle if you rev it up or start driving it it blows slightly warm air. The wierd thing is only left side vents blow warm air right side blows cold. On floor left side blows warm right side cold, on defrost left side warm right side cold. I havent felt heater core lines for temp yet. I am suspecting a door inside the heater box is not shutting or opening as required. The vent selector and heat control selector both seem to be working properly. Any ideas is a great help.

My 92 corsica does not blow warm air out of the vents at idle if you rev it up or start driving it it blows slightly warm air. The wierd thing is only left side vents blow warm air right side blows cold. On floor left side blows warm right side cold, on defrost left side warm right side cold. I havent felt heater core lines for temp yet. I am suspecting a door inside the heater box is not shutting or opening as required. The vent selector and heat control selector both seem to be working properly. Any ideas is a great help.


Does your temp gauge go up an down? I know on my 94 I'm having the smae problem but the sides are the other way around left is cool to warm an right is very warm.. but the temp guage moves from 3/4 mark back to 1/4 mark hot air comes then the cold air starts blowing.. Look under your dash be right about where your knee will be an see if the rubber hose to the black box is off or just barely on.. the black box im speaking of is the black box that goes over the heater core black cover... follow that up to your dash an an both sides should be where the hoses are to hook up to each side hope this helps.. If not an you fix it could you please let us know what ya did to fix it.. Thanks