AC Controls hissing from dash when turned off

**kb274868** · 07-15-2010, 08:14 AM

This problem started yesterday. When I have the AC on everything appears to be working normal. The air is cold and when the levels on the dials are changed the amount of air coming out of the vents also change. But when the main AC switched is turned off, I get a hissing sound like air being released from a tire for around 3 seconds. It starts off loud and then slowly disapates. This is the nob that has the ac and max ac selection and only does it for this nob. Is this normal or is my AC Control Cluster need to be replaced? Thanks

**Spaz** · 07-15-2010, 08:56 AM

Originally Posted by kb274868

This problem started yesterday. When I have the AC on everything appears to be working normal. The air is cold and when the levels on the dials are changed the amount of air coming out of the vents also change. But when the main AC switched is turned off, I get a hissing sound like air being released from a tire for around 3 seconds. It starts off loud and then slowly disapates. This is the nob that has the ac and max ac selection and only does it for this nob. Is this normal or is my AC Control Cluster need to be replaced? Thanks

i had a truck that did that... mine would hiss then clunk then the cold air would start... i wouldn't worry about it... mine worked fine for a year (then i sold the truck...)

**rcorte3001** · 07-15-2010, 09:05 AM

lol thats completly normal the car has a manual switch valve that closes it from the a/c panel, its very normal to here that hiss sound especially on hot days

**Smittro** · 07-15-2010, 12:50 PM

Normal.. There are multiple Vac. lines that operate your control options.. What you're hearing is vaccume pressure being released from the line/s when switching from one selection to another. If the pressure could'nt be released from one line to the next your settings would'nt work... So very normal, and nothing to get concerned about.. If the sound does'nt go away then that's a sign of a vac. leak... If it does go away then it's doing what it always (like 99.9% of the time) should..