Tundra experts needed for AC issue

So I have an 08 DC. No climate control. Just the good old knobs to adjust the fan speed and temperature (hotter/colder). This just started happening. So when I start the truck the AC blows normally and cold for anywhere between 5-60 seconds then the whole system shuts off. Sometimes the lights next to the buttons stay on, and sometimes they shut off. If I shut the truck ignition off, then re-start the truck the AC will work normally and usually shut off as mentioned above. Sometimes it will stay on and blow cold like normal. Any thoughts?

 

Sounds like a refrigerant pressure issue.

 

When you say 'shut off', do you mean it stops blowing cold air, or air stops blowing completely?

 

Likely low on refrigerant. I'd highly recommend not just randomly shoving a can in and hop for the best and use pressure suction gauge set and look up R134A pressure chart for your ambient temperature and see if it needs coolant.

 

Shuts off completely. Stops blowing air period.

 

So low refrigerant shuts down the whole system? Fan and everything? I can see how the fan would still blow, but no cold air with low refrigerant, or is shutting down the whole system just an indicator for low refrigerant?

 

Not necessarily Tundra specific, but generally there is a low pressure switch that has a requirement and a high pressure switch for safety. The low and high pressures must be in the proper range for proper function. I wouldn't expect that to affect fan function though. I think I saw somewhere that there is something called an A/C amplifier under the dash, but I don't know enough about it yet to direct you much. Might see something in this thread....https://www.tundras.com/threads/failed-ac-amplifier.81064/

 

Have you checked your cab air filter? Probably not your issue, but if it is badly plugged it may be causing an overheat of the linear power module in the blower motor.

 

You may have a bad blower motor which is very common for Toyota. There is also a resistor ( or something like that, that can go bad as well ). The first thing I would do is, as soon as it stops blowing, check for power at the blower motor.

 

If it’s not the other suggestions. Some Toyotas will do this if ac relay contacts are getting bad. It’s normally located in fuse and relay box under the hood. Not too expensive. Hope you get it fixed soon.

 

This sounds more like a power delivery issue. The fan/blower motor should keep blowing even if its just hot air. If all the lights on the ac control panel are going dark is could be loosing power. Generally when a fault occurs in the AC system the AC amp(ecu) will flash the little lights on the control panel to show the ecu has an error.

I would start by checking and or replacing this fuse. 7. 5A ECU–IG No. 1

 

Codes?

 

No, my refrigerant completely emptied from a damaged line i didn't notice until the mid spring when the air was still warm. Also my fan motor blower was replaced a few years earlier because it was SUPER WEAK air flow & making noises at full power, fixed my air flow issue.