If your 2005 GMC Jimmy is only blowing cold air, it could be due to several reasons. Common issues include a low refrigerant level, which affects the air conditioning system's ability to cool, or a malfunctioning AC compressor. Additionally, a faulty blend door actuator may be stuck, preventing warm air from mixing with cold air. It's best to have a professional diagnose the issue to pinpoint the exact cause.
This means your Jimmy is pregnant with a Jenny.
You need to back flush the heater core have had to do it to my jimmy 2 times and fixed the problem is easy fix .
Because you set it that way
why does ac blow warm air? why does ac blow warm air?
Your heater will blow cold air only.
Bad thermostat
Thermostat and/or heater core may be defective
check your coolant level
it may blow cold air due to the fact that the heat anticipator on your thermostat may be set to long. you can change useing your owners manual for your thermostat but you should have a service tech do it
you may not have the heater water hoses plugged in
There are several causes that an air conditioner is only blowing cold air for a short period of time then only blow hot air and then not going back to cold. This is especially common in the hotter weather including in the 90s and above. It could be from the air conditioner freezing over. You can fix this by simple trouble shooting and if that doesn't work call a repair man.
Well it should blow cold while driving and stopped. You probably need to get your AC recharged. Hope I helped!!