ac control vacume line source

[tpjb57]

have a 89 k5 and the ac controller vacuum line is noy connected under the hood.
looked everywhere and there is no available empty line.
the round ball line goes to the cruise controller which the blazer does not have then it tees to the mass air sensor.
I'm missing something.
looked at all the diagrams.

thanks

 

[Craig 85]

I think this is the vacuum line diagram for your truck.

You must be registered for see images attach

 

[mibars]

The diagram should be right for 89 Blazer, ignoring the vacuum modulator for TH400.

MAP sensor, etc. should have separate vacuum sources, in form of two tubes going out of throttle body. Vacuum for HVAC and cruise (and transmission) comes out of the separate fitting towards the rear of the intake, not far away from distributor.

 

[tpjb57]

there is a line from the evrv solonoid to the t then cruise control servo then to the ball
I do not have cruise on the vehicle
the third port on the throttle body front has no suction
i can use a brake bleeder to create vacume on the supply line at the dash and all the servos work
so wht did the original line tie into?

 

[75gmck25]

This is the picture of my ‘75. The larger vacuum line coming out of the bottom of the reservoir/ball runs over to a manifold vacuum tree on the intake. You can also see the small vacuum line that runs across the plenum, and through the firewall to the dash controls. Your vacuum ball might be shaped differently, but it’s the same general design.

 

[84GMCSierra]

Sorry to jump in here, but is there a diagram like the one above for an 84 Sierra, base model, 350/TH400 with AC? Or is this diagram pretty much the same for all models with the exception of trans type?

 

[75gmck25]

I believe all with A/C have the same basic design, although the vacuum ball may be shaped a little different, and I’ve seen one mounted so the vacuum connections go sideways toward the drivers side.

All that canister does is provide a reservoir for vacuum, so when you accelerate and engine vacuum drops, the A/C controls still work properly.