1999 Chevy Astro Fan direction control

This is easy. There is a 6 millimeter black plastic vacuum line that is baked and cracked or seperated under the hood. This has killed your vacuum vent controls because there is no vacuum. On one end, it connects to a vacuum port on the intake manifold just behind the air conditioning compressor, just to the right of the engine intake. It runs under the black rubber flex hose between the air filter and the throttle body. It runs to the left and connects about 4 inches behind the washer fluid reservoir on the left. These bake and crack in half right under the intake black hose everytime. For now, you can find the break and splice it with a one inch peice of weedeater fuel line just plugging each end of the break into each end. Now, on mine, you have to pull the drink holder/glove box and the cowling, but I cut off each end of the line about 3 inches from the end, got a 2 foot piece of heavy wall 8 millimeter air line tubing, and plugged it into each end with a heavy coat of silicone RTV.

Good luck,

Ken