I always shut down the heat/ac system before I shut down the engine. I think it makes for easier starting and less wear on the electrical system....No science, just opinion.

 

I ALWAYS shut off everything before I kill it & I still get a mild clunk after start-up.

 

so I drove mine today and when I put the A/C on recycle it clunked pretty bad...that is the first time in a long time it has done it.
I think XLR8R might have it right.....I never really use the recycle mode but when I used it today it clunked...it must be the blend door??????

 

which mode is recycle, i always leave mine on the mode that draws air from the outside. and it clunks.

 

last two spots all the way to the left.......

 

i have never used that mode and i get the clunk.

 

isnt the blend door what is knowm for breaking?

 

I dont know what it could be then?????

yes thats the one

 

I still get the clunk but not as bad if I shut the A/C off. (sometimes) My issue is after the initial start up it has NO clunk all day. Even sitting at work for several hours. Only loud clunk I get is after it sits overnight.