A/C Heat Vent / Vacuum ??

[PigBoT]

Grand Cherokee is not changing from from the windshield vent. I'm not a mechanic but I believe I found the vacuum hoses and followed them around. They don't seem to be leaking or missing. There is an audible ticking noise coming from a component by the "evap service port" (i don't know that it necessarily has anything to do with it). Is there any way of maually checking my lines to try and located the problem, assuming that even is the problem?

[JUSTJEEPS]

Which hvac do you have? ATC or manual.
The tick is the purge solenoid on the firewall,Normal.

[PigBoT]

It is manual.

[JUSTJEEPS]

Ck the vac line running under the battery to the front bumper area it may be split. If all is holdng vac and the lines are ok check the Evap/heater box door arms sometimes they break.
Most likely its a vac problem.

[PigBoT]

Thanks Jeeps. Where is the Evap/heater box? And where are the arms that I should check?