Selector cuts out funny

[miller time]

I told my dad that it was not work well I found the vac line was melted by the header and could not find where it went so we found another vac line ok it worked went to leave I was running late so I got on it and it went to defrost I was like damn header I let out of it and it works fine lol I think it's funny as hell

 

[Earl43P]

Sounds like you ypassed the vacuum accumulator.
It sits under the airfilter box, bolted to the inner fender liner.

You have to pull out (literally) the airbox to see it.

There are two lines.
One from engine vacuum tree to accum, the other goes to the heater through the middle-ish of the firewall.

You'll find that what you've done is join the engine vac to firewall, bypassing the accumulator and checkvalve. Easy to fix. Get vacuum splices in the HELP section at the auto parts store.