Hey guys Ive been having a problem with my heat its an 86 efi 302 v8, anyway its in the first diverter in the system right after the fan... its the one that sends the air to either the upper dash vents or the rest of the system.... the rest of the system includes defrost, and heat... it has a/c... I can only reach and see the flapper through the second vent from the passenger side, I had to take out the register... anyway theres definetely a problem down there, and I cant figure out how to get to it.... do I have to go through the firewall? or through the dash...? its almost as if one side of the flapper has slipped out of its grove... but I can't see in there that far to know... the vacuum lines all work... the flapper even closes fine... but when opening it doesnt cut off the air to the upper registers... so I have no air getting to anything but the upper registers.... its kind of a pain cuz when we get moisture, the windows fog up and no defroster =( Thanks guys for any help or advice....