A/C Gone, No clue where to start

[Chew_12]

Ok so I was driving between two cities and then I noticed a burning smell, smelled like a mixture of things. Then I notice the A/C is not cold any more. So after that I turned off the car once I got home then restarted it. I notice that I have no control of the speed of the air. It randomly works but most of the time I cannot determine the speed of the air. I turned on the A/C and looked at the pulley and I looks like it is not turned when it is engaged and the truck makes a horrible sound. Im guessing the compressor is gone. However the whole A/C system was fixed about 5 years ago but not converted for some reason so I still have R-12. So right now whenever I start my car the compressor or something makes a really wierd sound like blowing air(it doesnt sound like a belt). I am worried this will screw up my truck somehow. I am not too concered about the A/C is out but I would like my heater to work and to control the speed of the air. So what do guys think happened? How should I fix it? How much is this going to cost me?

Thanks!

 

[Chew_12]

The compressor still may be good, the clutch is just not turning when it is engaged. BTW Im horrible with HVAC systems

 

[Chew_12]

Bump

 

[Jason94sport]

Well the speed problem should be the blower motor resister. It's monted to the right of the blower motor in the engine bay. That's an easy fix.

The AC probelm could be your compressor or lines. If you hear air by the compressor you might have a leak in that area.
1st step fix the speed, then get a leak test to see if you can hold pressure. You migth have to conveert to 134 anyway to get it working again. Most shops have stopped serviceing R12 systems. That means you would need a new compressor anyway to convert to 134.

 

[Chew_12]

Thanks for your input Jason. I dont have the money to convert to the R134 so can I just buy a belt that is for explorers without A/C? Is this resistor in the fuse box, or is it somewhere else? And would anyone have a clue why this all happened at once?

 

[Jason94sport]

It's mounted directly to the right of the blower motor. On the side of the heater box. There are pics floating around somewhere. It has a electric plug going into it.

 

[Chew_12]

Ok I replaced it, No change. I forgot to mention that there are different settings like low medium and high when i turn the switch however I cant regulate what setting it is on. So it will be on the off position and it will be on medium blow. I turn it to high and it is off. However this switches everytime I move the knob so I have no clue what position I am going to get.

 

[Glacier991]

I've been waiting for a fuller fleshing out of this issue. In the first gens... the compressor runs in a more or less closed electrical system, you merely need to energize it. To control temps you blend in warm air from the heater. So other than a compressor on/off switch, nothing inside the cabin affects it.

You describe airflow/fan type issues. Those are independent of the AC... except that the on/off switch is located in that same cluster

You need to isolate and fix your airflow/fan stuff first. I am not even convinced your AC is to blame. I sense your control unit head in that little panel is AFU. My 2 cents.

ps. I have some Auto AC background.

 

[Chew_12]

Glacier thanks for your input. I do believe the compressor has something to do with it, well that is definately a problem but may not be related to the air problem(but it is odd that is happened at the EXACT same time). The compressor makes a bad sound when the engine is on, I took a closer look at it and its not really a air sounds but more of a mechancal sound. The compressor, either the clutch or itself is definately bad. Right now I am not worried about the A/C. I just care about getting control of the air back.

As far as the fan, it works but I just cant control it. The switch does seem to work because it does switch sometimes to a different setting but just never in a normal order. So Glacier what do you think I need to replace?

Or would it be smarter to go to a shop and have them find the problem, then I fix it?

 

[Glacier991]

Let's start by unplugging the electrical fitting on top of your AC clutch. Take the AC out of the picture. Wrap it in a little saran wrap or the like, we may not need it for a while... do the same for the plug)

Next let's set the controls on vent... and tell me what happens as you change fan settings ? In other words let's explore the dimensions of your problem and see what we can divine along the way. Once we figure that out, we can address the AC issues (from your desctription they appear to exist... but might wait til next spring)

 

[Chew_12]

Alright removed the A/C plug and its still doing the same thing. Ill try to explain what is doing a little better. The position of the knob has no say in the speed of the fan. If i turn it higher the fan sometimes goes slower, faster, or stops depending on the previous position. Same thing if I turn it to the off position or turn it down. One thing I did notice is that is does not jump from a High setting to a off setting, in other words it will not skip between settings( another example it will not go Low to high, it has to go from High to Medium then to Low then to off. or the opposite) . Am I explaining the problem good enough?

 

[Jason94sport]

You could have a bad blower motor relay also. I had that go. That is in the fuse box under the hood. Should be labeled on the back of the lid which relay it is.

 

[Chew_12]

If the relay was bad wouldnt the blower just stop blowing?

 

[Chew_12]

Well now when I turn the knob it hardly switches at all. I never can get it to go off. It normaly stays on high - medium high setting.

 

[Chew_12]

Well I replaced the Belt today to a non A/C one. I got tired of the noise it was making. It did not effect the fan at all, which i was guessing. I did take out the relay so that it wasnt blowing all the time and after I took it out it was pretty hot. I dont know how hot they are supposed to get, but the car was only on for like 15 minutes and I could almost not hold it in one hand. I will replace that this weekend and I will let you know how it goes.

 

[Chew_12]

I replaced the Relay...Nothing Changed

 

[Brock94]

It sounds to me, and I think Glacier said this above, like the control panel is shot. When the resistor goes, you usually only have the high setting, but nothing in between works. If the selector switch is broken internally, it could cause the symptoms you described.

I haven't looked at the resistor in the Explorer, but if one of the coils broke and is now shorting with the other coils in the resistor, it could also cause the random speed changes you're talking about.

 

[Chew_12]

Yea the resistor and the relay were changed. I guess I have to take apart the dash to replace the selector switch?

 

[Brock94]

Yea the resistor and the relay were changed. I guess I have to take apart the dash to replace the selector switch?

Yup. Shoulda listened to Glacier in the first place. He knows his stuff.

 

[Chew_12]

Thanks brock for your much needed input