heater not working help!!!!!!
Thread Starter
Intermediate
Joined: Oct 2010
Posts: 25
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yes I cahnge out the control panel on the dask thinking that would fix it ,but no and there isno vac lines going to it .took the dash out and the panel agian looking I found the vac line on top by the wind shield looks like goes to an accutor for the defrost but it does not blow hot either
Le Mans Master
Joined: Aug 2000
Posts: 8,838
Likes: 31
From: Australia
C68 is the Electronic unit
The head unit ( in dash ) electrically operates a remote mounted vac control unit that controls the vent motors
http://www.batee.com/corvette/acrepa...oard/index.htm
but that only controls the vent positions.
If you can not change vent position you have no vac from engine ( common ) or other problems with control side of system
The heat is separately controlled by a door operated by a electric motor that is also controlled by the head unit.
Have you confirmed you have hot water to the heater by checking both hoses going to the heater in the engine bay ?
May have blocked heater core
The head unit ( in dash ) electrically operates a remote mounted vac control unit that controls the vent motors
http://www.batee.com/corvette/acrepa...oard/index.htm
but that only controls the vent positions.
If you can not change vent position you have no vac from engine ( common ) or other problems with control side of system
The heat is separately controlled by a door operated by a electric motor that is also controlled by the head unit.
Have you confirmed you have hot water to the heater by checking both hoses going to the heater in the engine bay ?
May have blocked heater core
Last edited by rodj; Nov 2, 2010 at 08:03 AM.
Thread Starter
Intermediate
Joined: Oct 2010
Posts: 25
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I do have water flow through the heater core but on ething I did find is that I have no vaccum at the defrost acuator I pulla line of the vaccum ball up by the driver side head light and ran it to that acuuator but still will not get warm ,were are the vacuum tree for the dole system thats were i think my porblem lies ???????
Le Mans Master
Joined: Aug 2000
Posts: 8,838
Likes: 31
From: Australia
Heat is not controlled by vac.Vac only controls vent position.
You appear to have two seperate problems
Can you change vent positions?
Vac line comes off pass side rear of intake to one way valve by dist.Splits at valve ( often broken ) ; one line goes inside for HVAC , the other line goes to a T for cruise control and continues to vac ball.
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Thread Starter
Intermediate
Joined: Oct 2010
Posts: 25
Likes: 0
well the cruise works and the line going to the ball had vac so you are saying that not have heat is a electric problem not vac. so is there a electric switch that could be bad and where is it located
Burning Brakes
Joined: Apr 2009
Posts: 877
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From: Broken Arrow Oklahoma
the vac goes to the AC / heater programmer and it controls the air direction.
I would guess that the blend doors are not opening correctly.
there is a motor that operates the door. Sometimes the plastic keeper breaks and the rod falls out.
I would guess that the blend doors are not opening correctly.
there is a motor that operates the door. Sometimes the plastic keeper breaks and the rod falls out.
Le Mans Master
Joined: Dec 2000
Posts: 7,839
Likes: 22
From: San Diego, Ca
Just remove the Blower Module on the left side of the Evaporator Case and look inside to observe the door while someone punches 60/90. If it it's moving, the heater core is plugged up and you can try to flush it out, though you often need to replace it. If it is plugged up, I'd have the radiator hot tanked or replace it too and check #7 for a leaking head gasket which is what causes all the stoppage in the '89 cooling system.
Thread Starter
Intermediate
Joined: Oct 2010
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I pulled it all apart today I found three vac actuators one at defrost one at heater core blend door and one in the middle of the dash behind the radio ,I traced the vac hoses down to a black box under the driverside and it has a weather pack connector (power) going in and a vac connector with a multinumber of colored vac lines going out is this the vac pump you were talking about ??? and if so is there any way to test it (I dont like being a parts changer)
Safety Car
Joined: Jan 2004
Posts: 3,556
Likes: 13
As as been stated above, vac does NOT control heat.
There is a elec motor that moves the blend door to control air flowing over the heater core
Motor has a arm to the blend door inside ducting and is visible from under the dash
Follow SunCr's recommendation and look inside ducting to see if blend door moves when temp setting is changed
View looking up under dash from floor
There is a elec motor that moves the blend door to control air flowing over the heater core
Motor has a arm to the blend door inside ducting and is visible from under the dash
Follow SunCr's recommendation and look inside ducting to see if blend door moves when temp setting is changed
View looking up under dash from floor
Last edited by vetteoz; Nov 3, 2010 at 10:59 PM.
Thread Starter
Intermediate
Joined: Oct 2010
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the pic you sent at what point of the dash is this located mine does not look like this .are is this behind the what i call the 80s air bag the cushion on the dash of pass side that I have not removed yet???????
Burning Brakes
Joined: Apr 2009
Posts: 877
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From: Broken Arrow Oklahoma
what you found under the dash on the drivers side is the a/c heater programmer. Usually if you have problems with air flow control, this unit seems to be the problem.
I don't think it effects the heat itself.
I don't think it effects the heat itself.
Thread Starter
Intermediate
Joined: Oct 2010
Posts: 25
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Heater not working
Found out today that I have no electricial issues the rod on the motor is on and working fine .my friend came and help he is better mechanic than i he is saying im not geeting enough vaccum to the acuators all the door are staying open .What im needing help with is knowing the location that the vac comes in for engine compartment . so can some one send me the vac. diagram for the 1989 vette thanks Duke of Earl