I just bought a 2000 S70 with 69,000 miles. The ETS was replaced at 49,000 and the evaporator at 58,000. But this is the first time I've had an Electronic Climate Control and not sure if it is broken or I just don't get it. There is definate crackle or gurgling under the dash after the car interior warms up. I have it set at 72 degrees and the blower on either Auto, Zero or low, but I have the AC off (its winter). Seems to happen after the car warms up and it may be getting slightly warmer inside due to the sun rays outside?? When I turn on the AC I don't seem to notice any crackling. The manual says the AC will "function best if always left on" OK then why it there an Off switch.. Is this crackling because I have the AC off and the car it getting a little warmer that the temp setting. Still why should it crackling anyway. And how does one completle turn off the heating and/or air in these cars with ECC (not just the blower) I looked at the Volvo records of the previous owner and at 64,000 she took it back several times to the dealer about this crackling noise. Maybe she dis keep the AC on either because it was winter. Once time the Dealer replaced the wire harness and the other times they apparently could duplicate the problem.

Am I going nuts? Is this crackling (no smoke or smell) something I should be worried about? Why would is crackle anywhy if the AC was off..

Any thoughts might help me to sleep better.