Please look at this pic:
I can't figure out what the black WIRE is that is coming from the right side of the 'T' in the vacuum line...the vacuum line coming in from the left is from the vac. storage tank behind the headlight. The line going DOWN goes to the vacuum check valve, on to the filter, [I've cheked the check valve, and it's GOOD...the filter, however, was crumbled inside & needs replacing] and then to the right front of the carb. The WIRE goes thru a grommet on the pass. side firwall into the "under dash" area. (I haven't tried to find where it goes under the dash YET). For the life of me, I can't figure out WHY a WIRE would be hooked to a vacuum line.....

Reason I'm asking this is that I'm chasing down a vacuum leak....so far I've found that the fitting on the headlight actuator with theGREEN vac. hose that opens the drvr. side headlight won't hold a vacuum [YES, I checked the vacuum with the hose disconnected, & checked the vacuum right on the fitting on the actuator itself. Procedure says that if this port won't hold a vacuum that the GROMMET has to be replaced...so I'm gonna order rebuild kits for BOTH actuators.
ANYWAY...and input for this WIRE would be greatly appreciated!!

INFO: This is NOT the stock engine....I had a 350 4 bolt block built to around 400 hp....It hasn't given me any problems until I lost my power assist from the vac. brake booster....and I started the "leak" check scenario to see if the booster is bad, or a leak in the vacuum system...so far I've found this leak.....
I can't disconnect & plug the vacuum line coming from the front right of the carb & run the vac. line from the rear of the intake directly to the booster as a check, as the engine just plain won't start or run right, so that lead me to a vacuum leak.....SO FAR!
Again....THANX for ANY feedback!

 

It's not a wire. A a small vacuum line, it goes to the a/c controls, and it's used to open and close the vents.

 

Assuming from your other post about 1979, here are some factory schematic of the 1979 vacuum hoses for a car with AC... Hope this helps you.... but I don't see green or pink.

 

Willcox: my car does NOT have a/c. Also, don't pay attention to the green & pink wires, as it's an illusion...they are BEHIND this T, and do not relate to my question.
I also don't have a heater core, hence no need for utilizing the heater/defroster control....unless I need to know if it IS leaking!!

"SO....As I don't have a/c, does this "small vac. line" even affect ANYTHING on my car?

Are you sure this small vac. line doesn't go to the heater/defroster switch....as I thought this switch has vac. lines connected to it??

 

It goes to this switch. Doesn't matter if you have ac or not.

 

Does the car have Cruise control? I'm kind of lost on this but I have a cruise vacuum schematic on my tech site... http://repairs.willcoxcorvette.com/w...iagnostics.pdf

It kind of looks like a cruise control vacuum T.. that someone has forced two vacuum hoses into...

Also... Nothing I have here shows the colors on the vacuum lines the OP posted above... I think someone just added what they needed to make the system work.

I posted the factory AC schematic above, and the one posted below is the No AC schematic... Neither a/c or no a/c shows the color hoses in the OP's original post.. I've used these schematics for years.. so I have no reason to doubt the authenticity.

 

Willcox, I believe you have become confused, the OP was asking about the small black vacuum hose connected to the tee. The green and pink wires are just in the background of the photo.

 

WHAT ANTZ81 said: It's ONLY the BLACK wire I'm talking about.
NO, it doesn't have cruise control.

SO....Antz, you're saying it goes to the heater/defroster switch?

As I'm NOT using the heater or defroster, should I still verify that the small black VACUUM line & switch connections will maintain a vacuum? Would I be ok if I was to pinch off this line? WHY isn't this small vac. line shown on the vacuum system for my '79???

 

Yes it goes to the heater/defroster switch, as per the last diagram that Wilcox posted.

Yes check they still hold vacuum. If this line was to be disconnected, it would be the same as having the switch stuck in the off position. For some reason this diagram was left off, only place to find them was in the heater / ac section of the FSM (that I know of anyway)

 

Confusing! If this really is a black wire in a rubber tube connected to a vacuum tee, I'd say that it may be a Bubba plug of a hole that he wanted capped.

 

larrywalk: After a lot o' investigating & talking w/ lots o' people, it IS a small tube that
goes to the heater/defroster/ac switch....which I WILL cap off, as I have taken out the defective heater core, and I am not going to replace it, as I don't intend to drive in cold weather, and it doesn't have a/c...so I'll remedy ANY possibility of a vacuum leak!!
Thanks again to everyone for all you input!!