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Gary, Australia Car Mechanic
Category: Australia Car
Satisfied Customers: 1186
Experience:  Senior Technician
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Vs commodore with climate control, heater won't work. A/c

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Vs commodore with climate control, heater won't work. A/c and fan works perfectly but when setting temperature to heat car, blows cold air. Any help would be appreciated! Thanks, Mark
JA: Have you checked the coolant level? Have you checked for a leak in the radiator?
Customer: Coolant level is good and radiator is working well, no leaks
JA: What year is your VS Commodore?
Customer: 1996
JA: Are you fixing your VS Commodore yourself? What have you tried so far?
Customer: Fixing myself, haven't tried anything with heater so far, don't know where to start...
JA: Anything else you want the mechanic to know before I connect you?
Customer: Had car since February, running well. That's it, thanks!

Hello! My name is Gary.
Welcome to JustAnswer.
I'm reviewing your question now, and will post back with a reply shortly.

Hi Mark,

What engine in your VS?

If you have bought this car 2nd hand, are the heater hoses connected at the firewall?

If they are connected normally, can you check the heater tap vacuum valve operates in both positions?

The heater tap is in the RH side of the engine bay.


Customer: replied 4 months ago.
Standard V6, car was bought second hand. All heater hoses are connected from radiator to firewall.

ok, sounds good to start with.

When the engine is at operating temperature, do the heater hoses get hot up to the firewall?

Can you check the heater tap changes direction when you ask for cold or hot?


Customer: replied 4 months ago.
The hoses are getting hot all the way to the firewall. I did not notice a change of tap direction when ask for high temperature or low temperature.

So the vacuum supply to the heater tap is not working.

Can you also check if you can operate the heater tap manually by pushing on the lever where the vacuum actuator pullrod goes?

Your problem could be a vacuum supply to the cabin, a solenoid pack fault, or some other faults.


Customer: replied 4 months ago.
The lever on the vacuum actuated pullrod does not move, even with a fair amount of pressure, either way

So does it feel like the heater tap is jammed?

If this is the case, replace the heater tap assembly.

Note the way all hoses go, most important.

This is the heater valve in the heater hoses in the engine bay .

With the engine off the valve should be easy to move.


Hello again,

Do you need any further help?

I hope my advice has been of assistance to you.

Kind regards


Customer: replied 4 months ago.
Hi Gary,I have just replaced the heater tap assembly with a new 1. When setting the temperature between hot and cold the lever definately moves.I still have cold air blowing in. I replaced the hoses exactly how they were but I think the assembly was put on wrong in the past? I have attached a photo to show how it is set up.Thanks,

Hi Mark,

So the old heater tap was not moving, but the new one does move from hot to cold now?

Your installation looks correct for VS.

Are you bleeding the cooling system correctly after changing the heater tap?

Perhaps you have an airmix door problem inside the HVAC case, either actuator or flap.


Customer: replied 4 months ago.
Hi Gary,Should I changeover the climate control module? I have 1 off an old vs that I know works...Mark

Hi Mark,

That's great if have a working spare.

Let's swap it and see what happens.


Customer: replied 3 months ago.
Swapped the climate control module and flushed and bled the radiator system. Radiator system working fine , new climate module working fine, still no hot air blowing!Thanks,

Hi Mark,

Looks like you are now looking at why the airmix door actuator is not moving.

Possibly a vacuum solenoid issue, wiring between the climate module and the solenoid pack, a vacuum leak in underdash hose etc.

Start at the vacuum supply hose from the engine with a mityvac vacuum pump tester, to see when the loss of vacuum occurs.

You also need to watch all the actuators function to determine which one is not moving.


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