Heat/air

[Rconard]

I have a 2000 sonoma. When I run the ac or the defrost it will stop blowing after about 15 minutes. If I run any other setting it will run forever.

[Jsdirt]

Sounds like the evaporator might be plugging up with ice. If the blower motor continues to run, but airflow stops, this is the most likely cause. That usually happens from a bad low pressure cutoff switch, usually found on the accumulator (silver canister on passenger side firewall with the A/C lines connected to it).

Edited January 5, 2021 by Jsdirt

[Rconard]

Ok I will give it a shot. I just replaced the low pressure switch last year but anything is possible.

Thanks 

[Rconard]

Ok I did not change the low pressure switch yet. Was playing around with it the other day and I figured out now that it stops blowing no matter what mode I have it on. It just seems to stop blowing a little quicker with the ac or defrost on. 

[Jsdirt]

Might be time for a new motor, or resistor. resistor failures were very common in those year models.

[Rconard]

Ok thanks for the help

[Jsdirt]

Before replacing anything, confirm that the motor is not working, and that you have power at the resistor, and at the motor connector. If you don't have power to the resistor, you have another issue, and replacing that won't fix the problem. If you have power at the motor on some fan settings, but not others, then the resistor is bad. Usually when a resistor goes bad, you'll have fan operation on high only, and not any of the lower settings. I've seen them fail a myriad of different ways, too, but that way is the most common.