A/c Not Working So Well....

[bigwhitesierra]

bought an 05 Sierra 2500 back in November...31,000 miles. Hadent used the A/C until yesterday. Now that I am using it, its not nearly as cold as it should be, and I'm hearing an intermetant "whistling" noise from somewhere in the truck (almost sounds like the transmission area). Any ideas????

[Draenor]

Get it charged. Do you have a guage to check the Hi/Low pressure?

Is the whistling occuring with the A/C?

[hubbycap]

Does the whistle change if switched between recirc and fresh. Could be an air leak if only occuring if in outside air mode.

[bigwhitesierra]

yea....whistling is happening only when a/c is on. tried changing between recurc and fresh air....no change in noise.

[Draenor]

sounds like its pointing to failing bearing in the fan motor. Can you climb up under the dash and listen to it?

[hubbycap]

sounds like its pointing to failing bearing in the fan motor. Can you climb up under the dash and listen to it?

 

Only when a/c is on? It won't whistle if you have it in ventilation or heat and fan is on? Does it change pitch with fan speed?

[bigwhitesierra]

Only when a/c is on? It won't whistle if you have it in ventilation or heat and fan is on? Does it change pitch with fan speed?

 

 

 

Ive only noticed it after i attempted to use a/c. dont hear it when heat or just ventilation is on. Going to call dealer 1st thing Monday morning....but was trying to see if anyone had any ideas on here 1st. Thanks for the input...keep any ideas coming!