Tundra AC self adjusts

I have an 08 tundra with standard climate control. The AC fan speed started adjusting itself, it’s now progressed to where it will actually start blowing hot air. Seems to go away after I run for awhile but it is getting worse. Any ideas

 

You could have a damper sticking but sounds like you need to check the freon level and go from there. If you don't have a lot of experience in refrigeration probably better to take it somewhere for a diagnosis. Without gauges and stuff you're pretty much guessing.

 

Thanks for your reply. Don’t think it’s Freon as it blows cold when it works right. The blower fan will adjust from hi to low and back without me touching it.

 

I'm not familiar with a 2008. Are you saying that it has a temp control option as in you set it to a temp and not a manual temp control?

 

No it’s all manual control.

 

I would say it sounds like a blend door problem. Or more than one. Start by opening the glove box and removing the filter. You should be able to see the fresh air blend door and, if I’m remembering correctly, another blend door. Check for function, it’s possible that the volume of air is pushing the doors open and closed. You may even have an obstruction. It’s also possible that the fan itself may have a problem. You can actually watch the fan do its work with the filter out. This can help you dial it down to what the problem is. If the fan is slowing itself down even with the filter and access door out I would say it’s probably time to change the fan. Hopefully it doesn’t have anything to do with the control panel.

 

Sounds like you have a fan or fan controller issue. Like15 says, you need to observe the damper. If you're starting on hi the blower motor may be finally able to ramp up. If you're on low and it starts going higher, I'd start pricing out a fan and controller. Going without AC in these parts isn't an option during the summer. I was looking at rock auto and a blower is $60 and a damper blend door actuator is $40. Don't see a controller listed.

If you're not moving enough air through the coil you can also trip the compressor pressure switch.

 

Thanks I’ll try that