Intermittent issue A/C weak air flow

1997 GMC SIERRA
186,000 MILES • 5.7L • V8 • 4WD • AUTOMATIC
Avatar
PHILLIP19
  • MEMBER
  • 1 POST
A/C blows good and sometimes it doesn’t.
Aug 19, 2021 at 9:19 AM
Advertisement
Avatar
KASEKENNY
  • Experienced Mechanic
  • 18,907 POSTS
I assume you mean the blower motor doesn't always blow consistently. If this is the case then we need to monitor the voltage on the blower when it happens.

Basically we need to see if the blower motor is the issue, the ground, or the resistor that sends voltage to the blower is the issue.

https://www.2carpros.com/articles/low-or-no-air-flow-from-vents

https://www.2carpros.com/articles/how-to-check-wiring

Below you will find the wiring diagram that we need in order to find out if the blower motor is getting proper voltage.

If this is not your issue and the issue is actually the A/C just doesn't blow cold at times, then we need to check the pressure of the system when this is not blowing cold.

https://www.2carpros.com/articles/re-charge-an-air-conditioner-system

Please let us know if you have other questions and we can go from there. Thanks
Aug 21, 2021 at 8:53 AM
Join 2CarPros for free, one of the most advanced car repair communities on the internet. From first-time drivers to seasoned mechanics, everyone is welcome to reply, share details, and get better answers. You can add a temporary image or video first; uploads are limited to 20 MB.
Ask a Free Question
Repair Safety Notice: This information is for general instructional purposes only. Vehicle repair can be dangerous. Verify all information, follow manufacturer service procedures, use proper tools and safety equipment, and consult a qualified repair shop when needed.