I can't tell from the pictures, but I'd recommend sealing around the edges too. Just a small, neat bead seal.

 

now it works, when i got this truck i went through and replaced a few blown fuses not knowing what they were for, but after looking at the faq someone put a 5 amp fuse in when its needs to be a 30 for the heater fan. now the fan works but it only works on defrost. but its better than nothing.

 

As far as the heater working only on defrost, that is either a vacuum problem (in the event of a loss of vacuum, it will default to defrost position for safety purposes [windshield will be able to stay clear]). Or, there is a fault in the mechanical, which is not allowing the doors to move, and therefor, not allowing air to flow thru the other vents.

 

Yeah those pics were taken before I put the grommet in where the wire comes out. There is a gasket in behind the metal plate to keep the water out and there is a bead of silicone behind the box where it attaches to the firewall.

At first I was afraid that it wouldn't get enough air flow so I didn't put the grommet in but, it gets plenty with the grommet in.

 

im almost positive its a vacuum problem. there is a vac. line by the gas pedal and i dont know where it came from. and one is off that comes from the vacuum reservoir under the hood. i cant find the other end for that one either.

 

i just fixed mine and all it was is a broken lead and the spads wear the harnes hoked up were corded so i cleaned and it works now