Door in vent box is not opening for the drivers side. Probably a bad vacuum line to the diaghram. If there is not a separate door than single door is not opening all the way. Also check for obstruction in the vent
Had the same problem. In my case it was the actuator motor inside of the panel in the passenger footwell. Check to see if the flap is binding or it is the actuator motor itself.
When my a/c system is low on refrigerant, it blows hot on drivers side, cold on passenger side of the dashboard. This is a 1997 Buick Ultra. Recharging the system solves the problem.
Your climate control in your 1998 Ford E250 Cargo Van blows cold air when in heat position and sometimes it blows warm air when in the cold position?
make sure both knobs are all the way up on red for heat...
Defective actuator behind glove box that controls air flow.
You most likely require an A/C system recharge. There should be a temp sensor under the hood near the passenger firewall connected between heater hoses to control the ac and heater temperature. Replace that first.
If the air conditioning only blows cold air on the passenger side, it may indicate a problem with the vehicle's climate control system. Possible causes include a malfunctioning blend door actuator, which regulates airflow and temperature, or a refrigerant leak affecting the system's performance. Additionally, issues with the climate control settings or a failing compressor can also lead to uneven cooling. It's advisable to have the system diagnosed by a professional to identify and resolve the issue accurately.
Some 1887 Corvettes came with separate driver and passenger climate controls. The most likely cause is the control system, running a self test will show if the vent doors are operating properly. If the control is ok then the diverter door system is stuck.,
Check your climate control switches, and vaccuum lines. If you have electronic climate control, you probably need to have it serviced. Quite often in Grand Am's 91-2002 have had minor problems with weak linkages within the housing and routing of the climate control rod's and lines.
heater control valve is bad on the drivers side.
This may be a cause... My wife's 95 contour had to have the vacuum temp settings control unit replace 2 times. If you are constantly changing settings it really blows the valves in the climate control center... Just a thought.
The most common issue is the heater / climate control valve. This can usually be tested in dual mode and checking for change in air circulation.