help...vacuum experts out here
 

I am currently trying to find a vacuum leak in the system. Does anyone have a vacuum diagram for an 84 300TDT. I have a solid black vacuum hose going thru the fire wall together with the A/C, door locks, ignition vacuum hoses. The diagram on the cowl sticker doesnt show where the black hose leads to inside under the dash. When I looked under the dash, cant seem to find where it is attached. Can anyone help me with this.
- Tippee
84' 300tdt
84' 240D
84' 230E
66' 250SE

vacuum
 

It's a vent, and doesn't attach to anything, it just appears to dangle in mid-air under the dash, if it's the correct colour and not an add-on. |The lines going through the firewall that are part of the C/L system are yellow with green/red stripes, and purple for headlights, brown for ignition switch.