Vn v8 no vaccume to heater tap plz help

[Gmvn5l]

Hi guys I have a vn v8
Climate controll
There’s no vaccume to heater tap.
Iv checked everything

I checked one way valve behind manifold
Checked ball on passenger side behind bumper
Checked all hoses inside car
Checked heater box

Checked literally everything.
Blew air threw all hoses

Brand new heater tap
New core
New hoses
Iv rebuilt the whole car

I cannot for the life of me
Get vaccume to the heater tap
And the heater just blows cold.


What could it be

Kinda need a heater in the car.

Thanks guys

 

[Fu Manchu]

Faulty heater tap?

It’s engine to heater controls, and from heater controls to heater tap.

From a vague recollection of my VP, there is an arm/rod from the heater dial that controls vacuum to the heater tap? Are the linkages all connected up?

 

[Immortality]

^^^^ Correct.

From the drivers side footwell area looking at the area behind the heater controls there is a small vacuum switch that is controlled by a rod connected to the temperature adjustment knob, Rotate the temperature adjustment knob and you should see the rod moving, IIRC when it's fully on the cold setting it should push the vacuum plunger in cutting off vacuum.

 

[Gmvn5l]

Faulty heater tap?

It’s engine to heater controls, and from heater controls to heater tap.

From a vague recollection of my VP, there is an arm/rod from the heater dial that controls vacuum to the heater tap? Are the linkages all connected up?

Brand new heater tap mate.
My heater box is for climate controll there’s no rod on the climate controll as it’s all three the climate controll buttons correct

 

[Gmvn5l]

^^^^ Correct.

From the drivers side footwell area looking at the area behind the heater controls there is a small vacuum switch that is controlled by a rod connected to the temperature adjustment knob, Rotate the temperature adjustment knob and you should see the rod moving, IIRC when it's fully on the cold setting it should push the vacuum plunger in cutting off vacuum.

Is that on a manual one not climate control. My vn is climate controll

 

[Gmvn5l]

all my vaccume hoses run to a vaccume block under heater box Behind sterio.
It’s not a manual heater controll knobs.

It’s all electronic via climate controll

 

[Immortality]

Then you need to check all the vacuum connections and if those all check out fine then you need to check/test the vacuum block.

 

[Lex]

deleted

 

[MikeC]

New core! Getting serious.
Make sure you have a good heater tap- I had an opening failure until I threw out the replacement supposedly GMH tap and installed a Gates.
After that you may have a control system problem.
Check the wiring and connections to the solenoid pack at the back of the radio as much as you can.Check for creased or damaged hoses.The heater water valve hose is yellow and the vacuum source hose is black
Have you run through the self diagnosis program on the climate control. It's detailed on the forum but basically you start by pressing the CC off button within 10 secs of switching the ignition on. Push the hot button each time the CC finishes testing to start testing the next group of control software/sensors.

When you get to modes you should have :
step-Valve state
31-closed
32-closed
33-open
34-open
35-open

If you can check the heater valve solenoid it should have 12V when the valve is closed.

 

[Gmvn5l]

Then you need to check all the vacuum connections and if those all check out fine then you need to check/test the vacuum block.

Checked everything tested everything. Still no luck heater core is hot hoses are hot still won’t blow hot air it’s got me stumped