all air is blowing through defrost. Would think its a vacuum issue. There are two black hoses just off the batter towards the firewall. One runs to the back behind the battery over right fronttire well apparently and appears to be attached. The other is disconnected and based on length, must attach somehwere in the near the battery. It is attached to the same housing at the wire that is apparently not disconnected and it comes from the top of the attachment Any suggestions? I took the battery out but I don't see where it this black wire could attach.

 

gochiefs,
Is this on the '98 F150 in your Profile or a different vehicle??

 

98 F150 4.6 L

 

yes, you have a vacuum leak. look from the battery toward the fire wall and you will see a small hose maybe 1/8 inch diameter go thru the firewall by itself. that is the vacuum to the heater controls. outside the fire wall the tube comes out a few inches then has a TEE. one end goes toward the battery and has a canister behind the battery to "store" the vacuum. it is an accumulator. the other side of the TEE goes to the engine intake manifold area and plugs into a fitting. that is where the vacuum begins. i have the 5.4 motor, so the description might be a little generic for you.