03 owners with low A/C output at idle

[Matt400]

There is a simple way to determine if your 03 needs the TSB 18-043-03 done.

Start your truck and turn on the A/C full speed at idle in park.
Now walk around to the front and listen for the Vistronic Fan to start pulling more air through the grill.
If you hear your A/C compressor cycling off and no fan roar then you need the TSB done. Inside vent temperatures will not be cold.

What happens is temperatures rise so high in the A/C the compressor cuts out for protection. With the TSB the fan will kick in pulling air through the condenser keeping pressures down so the compressor will continue to move refrigerant.