Munkee Posted July 16, 2012 Report Share Posted July 16, 2012 My car seems to always have the heater on, no matter what i set the controls to. The car had no AC (compressor and lines missing) when I bought it, but the previous owner gave me the parts to install if i wish (which I still havent). Since I bought the car in the winter it wasnt a big deal. now that its summer it seems that I cant shut the heater off no matter what I do w/ the ac controls. I can always feel hot air blowing from the vents and under the dash. I've noticed it blows more when on the freeway and not so much when at stoplights. I thought it might be the engine but I never see the temp gauge go above halfway so I assumed the engine temp was fine. I thought maybe something might be stuck in the heating/ac system. Any thoughts? Im still thinking of putting the AC back in but since I live in west TX and it's summer 10 months out of the year I was thinking of ripping the heating system out since I would rarely use it anyways. Is that possible? Link to comment Share on other sites More sharing options...
JohnnyWadd Posted July 16, 2012 Report Share Posted July 16, 2012 Sounds like the actuator is not working.......so to answer yes you could remove the heat by looping the heater core lines...but then when winter comes will you want it back? Soo time to troubleshoot... Link to comment Share on other sites More sharing options...
nomofwd Posted July 16, 2012 Report Share Posted July 16, 2012 (edited) Your problem sounds to be found in the control system itself, and not the heater core. The blower motor is not dedicated to the heat and removing the heater core will not stop air from blowing. Also if you removed the blower motor then you would have no a/c when you decided to put it back together. You need to find out if the controller of the components that it controls are to blame. Go get the FSM at www.starquestgarage.com and go through the troubleshooting flowcharts to diagnose. The first thing I would TRY though to make things a bit more comfortable and a first step in diagnosing would be to remove the number 12 fuse. This fuse feeds power to the blower motor relay. this should stop the blower from spinning and the hot air from coming out. If it does not stop the air then the relay is not shutting off even when the power is removed from the switched side. You can remove the number 5 fuse which is the actual power to the blower motor itself which is switched by the relay. Keep in mind that although you may stop air from blowing through the heater core and coming out of the vents, you still have hot coolant circulating through the core itself and it will get very hot. You may even damage the surround and insulation of the core. I've left my heat on in other cars with the blower off and would begin to smell burning plastic after a short time. So you say that no matter what you do to the control panel it doesn't change? Or just doesn't stop? If you press the high or low speed fan button does the air speed increase and decrease? When you press the buttons does it beep and the lights change accordingly? Also, the control unit operates a servo motor nearby your right foot (as seated on the drivers side) that operates the valve controlling coolant flow to the heater core. It is very nearby the accelerator pedal and as you increase or decrease temperature selection it should move up and down, pushing and pulling a rod leading to the heater core. On my car the linkage to this rod from the servo motor was disconnected, and the heat was essentially stuck on. It took days of scouring manuals and searching the web to finally find it and take 2 minutes to reconnect the motor. However if your blower is also unresponsive you may not have an issue here. Worth checking though. But, if all else fails and you really do decide that you are uninterested in finding the root of the problem you can disconect the servo motor from the linkage and operate it by hand. This would stop coolant flow to the heater core but still allow you to turn it on when it gets cold. I have no way of telling whether anything would work if you decided to re-install the a/c components though because if the control unit is faulty it likely won't operate. Edited July 16, 2012 by nomofwd Link to comment Share on other sites More sharing options...
dadrab Posted July 16, 2012 Report Share Posted July 16, 2012 It sounds over simplistic, but make sure you're doing your diagnosis in an air conditioned space. When it's 100 degrees outside and you're trying to tell whether the air coming out of a non-air conditioned vent is cooling off, it's naturally going to feel heated...all that's happening is the circulation of already hot air. Link to comment Share on other sites More sharing options...
Indiana Posted July 16, 2012 Report Share Posted July 16, 2012 The heater valve is controlled by a motor moved by the controller after the display is changed and just because you push "off" doesn't mean it stops the heat, you can't stop it completely . The door flappers are vacuum and actuators go out and the hoses fall off of them and the reference hose for them all runs over to the intake manifold Air is moving while you drive, if the doors inside are stuck and the valve isn't closed you can't stop the heat. You can put the fresh air button on recirculate that may help. You need to look under the dash on the passenger side and see if the hose fell of one of the actuators and if its connected under the hood. http://www.b2600turbo.com/images/hvacvac.jpg Link to comment Share on other sites More sharing options...
Skullzaflare Posted July 17, 2012 Report Share Posted July 17, 2012 there is 1 vacuum hose that runs out of the firewall near the passenger side, near the turbo shielding, that line runs to the alone nipple on the intake mani, that is the vacuum line for the climate controls, if its not hooked up it will always have hot air circulating throw face/floor/defrost vents Link to comment Share on other sites More sharing options...
tankbob Posted July 17, 2012 Report Share Posted July 17, 2012 My car's a/c and heater setup is very sketchy, my heater blew constantly until I just pulled out the fuse, no need for either here in socal Link to comment Share on other sites More sharing options...
kev Posted July 17, 2012 Report Share Posted July 17, 2012 there is 1 vacuum hose that runs out of the firewall near the passenger side, near the turbo shielding, that line runs to the alone nipple on the intake mani, that is the vacuum line for the climate controls, if its not hooked up it will always have hot air circulating throw face/floor/defrost vents The vacuum only controls the diaphrams that adjust the exit vents. I.e. they only change it from defrost, face, foot, or combo face/foot. If you loose the vacuum, it will default to face/foot only. You will still have hot/cold features...these are controlled via a servo motor and not vacuum. kev Link to comment Share on other sites More sharing options...
kev Posted July 17, 2012 Report Share Posted July 17, 2012 Your issue may be a multitude of things: 1. the linkages on the flappers controlling the air flow past the heater core may be jammed up or disconnected2. the potentiometer attached to the servo motor may be faulty3. your servo motor may be faulty4. your control system may be faulty5. the cut off valve controlling coolant flow thru the heater core may be faulty. I'd get under your dash and disconnect the servo motor power cable (not the easiest thing to get to but it is possible to access without pulling the dash). Apply 12V to this connection...it will open/close the flappers controlling the air flow past the heater core. See if this will make it blow cold again. If it does, then it is a control issue rather than an issue with the heater box itself. Take a few minutes to study this thread: http://www.starquest...howtopic=131748 It doesn't address a control issue but will help you understand what is going on in the heater box itself. kev Link to comment Share on other sites More sharing options...
natallica Posted July 17, 2012 Report Share Posted July 17, 2012 How did I completely miss the thread posted above. Kudos for taking the time to do that Kev. I'm having issues with mine at the moment as well, and this will come in handy when I pull my dash...again Thanks-N8 Link to comment Share on other sites More sharing options...
kev Posted July 17, 2012 Report Share Posted July 17, 2012 How did I completely miss the thread posted above. Kudos for taking the time to do that Kev. I'm having issues with mine at the moment as well, and this will come in handy when I pull my dash...again Thanks-N8 You didn't miss it...I just made it yesterday, lol. Thanks, I hope it helps you out. kev Link to comment Share on other sites More sharing options...
nomofwd Posted July 17, 2012 Report Share Posted July 17, 2012 I have looked around and seen some say that reaching that plug is pretty difficult to do quickly, yet the motor can be disconnected from the linkage very easily and can be operated manually. You can see the servo move as you change the settings on the control panel. However to test the motor itself you would have to access the plug.. It all really depends on what your goals are. Link to comment Share on other sites More sharing options...
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