When I have the AC or Heater on ....right before I come to a complete stop at a light....I hear a rattle...which fades away as soon as I stop.

My tensioner shock was replaced 2 weeks ago....because the previous one was defective and came lose. Ever since that problem I have not had to use AC or Heater because of the Beautifull weather here in Cali...but yesterday with the heater on I can hear it.

This sound only comes up when AC/Heater is on.....However, when the system is on economic mode or off there is no rattle.

Again mind you that I can only hear as I come to a stop...

Any suggestions as to what the problem might be?

Could the lose shock have damaged my tensioner......which only rattle when it is under the stress of the working AC/Heater.

Or is this purely an Air condition type of problem. Blower, ....etc.

PLEASE HELP IS APPRECIATED

thanks