I'm about to purchase an 87 GXL. I'm picking it up next weekend.

And we've just found that the heater control valve is bad. I'm looking through the electronic version of the Service Manual, but I see nothing of it in there.

This would be under the cooling system, no? Since the heater core runs off the coolant...

I'm just looking to see if it'll be worth it to pay the $400 to have the dealership do it, or if I could hack it myself without ruining anything...you know the drill...

 

Are you talking about the valve itself or the acuator motor that flips the valve up and down? If the acuator motor is bad you can ghetto rig it like I did until you can find a working one.

 

well, I'm not totally sure yet. The seller had his dealership check it out, and they said the valve was bad.

I see that the problem could also be from the soldering points in the Logicon...

Geez, seems like it could be anything...

 

Let me tell you about my problem and see if it is the same as yours. What happened was that my temperature control does not work because the acuator motor that controls the heater core valve is broken. That valve determines what temperature the air entering the car is. If it is all the way shut you will never get any warm air, and vice-versa. That motor varies the valve position so you are nice and comfy. Me and my buddy rigged up a "pull-wire" to the flange that the acuator motor connects to. That way I could push it up to close the valve and pull down to open it.

 

well, as I said, I don't have the car yet...in fact, I've not even seen it in person yet.

However, I'm told that it blows some heat, but not much, so it sounds like that valve is stuck in a halfway kind of position.

My main question was the ease in which that valve could be accessed...

 

Well, if you are wanting to replace the valve I am not real sure how easy that is. We just rigged it this way until I can locate a replacment motor to acuate the valve. If it is truly stuck, your only option probably is to replace the assembly. Otherwise, when you get in possession of the car you can try just moving it by hand. If you are in the driver's seat, look down and to the right past the kickpanel. Underneath you should see a white flange with a wire on it connected to a small stepper motor of sorts. Try moving that flange back and forth, up and down... be gentle though mine was kind of brittle. Play with it a bit and if it can be moved you will know as it will make an audible "bump-clack" when it is opened or closed. Hope this helps.

 

It's a pain in the *** to replace the valve. However, it sounds like the motor is not opening and closing it. My valve was leaking so...

It can be done with out removing th e center console, it's just a lot of cusing and laying on your back. (like college) All in all, it can be done in a few hours, it just crammed in there and cutting and replacing the damn rubber hoses is a pain. Go for it. You'll enjoy it when it's done.

 

ok, thanks! I figure the first thing I'll do is take a look down there and see what it'll be like. I'm a big guy, so it's not easy to get under the dash in cars for me...my whole body hangs out...

If that looks ok, then it's on to checking the price of the part itself.

 

well, I have the car now, and I'm starting to think it is the actuator. I think I saw this part at mazdatrix.com, and it's not cheap...oh boy.

Anyway, I get NO heat.