2011 Buick LaCrosse HVAC issues

cooling fan does not work with ac on but works to keep engine cool. so when sitting still the ac does not cool

There are two fans.

One is for cooling the radiator and the other turns on when the AC is turned on.

Try running power directly to the AC fan to see if it operates. If it doesn’t operate replace the fan.

If does operate, then the circuit for the fan has to traced back to find out why it doesn’t function. Blown fuse, bad relay, etc…


There’s a separate fuse for each fan it appears. Number 42 is a J-type fuse for fan 2, Number 45 is for fan 1. Fan 1 is spec’d as the “left” fan, which I presume means the driver’s side. There’s a mini-fuse for the cooling fan relay, number 46. All located in the X50A fuse block, under the hood. This info is probably in your owners manual too.

There’s a separate mini-relay for each fan too. relay number 8 is the right fan, and relay number 13 is the left fan. Just to keep you guessing, there’s a micro-relay for the left fan speed control, relay 10.