Blend door questions

[98markviii]

I need a little help, my Mark VIIIs blend door is broken and I get no heat. But now that it's summer I also notice that I have no ac or cool air of any kind. And the air only comes out of the defrost vents. Is this all caused by my blend door?? And if so can I fix it with that little lever that's somewhere under the dash?

 

[dnsherrill]

does air come from the defrost (top dash) vent with EATC OFF and with car in motion? you could have a vac leak and the system is in fail-safe mode (defrost only)
I recently had a similar situation
http://www.lincolnvscadillac.com/forum/showthread.php?93354-No-A-C-general-TS

 

[98markviii]

I haven't tested that but it very well could be. I'm going to check the blend door error code tomorrow. If the vacuum is leaking (which is most likely caused by a cracked hose, correct?) Can I fix it by replacing that hose?

 

[dnsherrill]

in my case the vac leak was because one of the lines had been broken off the 3-port check valve located behind the pass side front fender liner, I reconnected it and air distribution commands were corrected...even with my system being in fail-safe mode my car made heat though, after I replaced the blend door (96 base)