Hello all!

My AC blows cold at highway speeds but slowly warms up if sitting still for too long. The compressor is functioning, and I have checked pressure on the low-side and it's reading as full. What I have noticed is that the aux fan is not coming on AT ALL. Is there a way to test the AUX fan while it is in the vehicle? I only have a basic scan tool and multi-meter - I do NOT have a tool that can trigger component operation.

Thank you!!

2006 X5 3.0 Auto