Intlcutlass Posted May 24, 2004 Report Share Posted May 24, 2004 Trying to diagnose: When I have the hood up, and turn the A/C on (engine running obviously) , I should here the A/C kick on right? Also, I remember from last year, the a/c worked fine when inb use, and then when we would turn the system off, we could see a fog comming out of the vents... Does this indicate a leak ? Right now when I turn the system on, it just blows warm air.... I am pretty sure the controls work , because if I turn the heat on , it goes from warm to Hot.... I really need help. we just had a baby, and it's really bad to go any sort of distance subjecting the little guy to excessive heat. Quote Link to comment Share on other sites More sharing options...
slick Posted May 24, 2004 Report Share Posted May 24, 2004 Wow, and i was just about to post the exact same thing. Did you check all your fuses and relays and crap? Is yours charged? Anyways, all my fuses and relays are good, and it has a full charge. But, when i hit the AC button, the engine acts as if the AC clutch just grabbed, but it didn't, because you can see that its not spinning(by just visually looking at it, you can see the clutch aside from the regular pulley). So, my problem is that the clutch isn't engaging. It's driving me nuts too, because i do a lot of highway driving, and can't stand to have the windows down while doing 70 mph. Help us! Quote Link to comment Share on other sites More sharing options...
Whiskey River Posted May 24, 2004 Report Share Posted May 24, 2004 Wow, and i was just about to post the exact same thing. Did you check all your fuses and relays and crap? Is yours charged? Anyways, all my fuses and relays are good, and it has a full charge. But, when i hit the AC button, the engine acts as if the AC clutch just grabbed, but it didn't, because you can see that its not spinning(by just visually looking at it, you can see the clutch aside from the regular pulley). So, my problem is that the clutch isn't engaging. It's driving me nuts too, because i do a lot of highway driving, and can't stand to have the windows down while doing 70 mph. Help us! Yours might be the pressure switch has gone bad. Mine does the same thing when it is cold out. If you short the leads in the relay box for the AC clutch, it should kick on, if it does, look into replacing that pressure switch. Intlcutlass: if you had some pressure readings then it would be easier to determine if you have a proper charge or not. You shouldn't have seen fog coming out of the vents. Quote Link to comment Share on other sites More sharing options...
DiscoStudd Posted May 24, 2004 Report Share Posted May 24, 2004 One thing I can add to the checklist: (This is assuming everything listed above checks out) Pull the electrical connector off of the AC compressor, and probe it with a voltmeter. Go in the car and switch on the AC and see if you're getting voltage to the compressor. If you're getting voltage, then I guess the compressor is shot. But, when i hit the AC button, the engine acts as if the AC clutch just grabbed, but it didn't, because you can see that its not spinning(by just visually looking at it, you can see the clutch aside from the regular pulley). That sounds like everything is working except for the compressor. Sounds like the ECM knows you're calling for AC, and it steps up the idle accordingly... I'm not an AC expert, just commenting on what I'd do before I break down and take it in to a service station... Quote Link to comment Share on other sites More sharing options...
godofthunder Posted May 24, 2004 Report Share Posted May 24, 2004 the fog coming out of the vents? Its normal. Its just the atmosphere....either really humid or not. Not to worry, unless its REALLY thick. jon Quote Link to comment Share on other sites More sharing options...
slick Posted May 24, 2004 Report Share Posted May 24, 2004 Yours might be the pressure switch has gone bad. Mine does the same thing when it is cold out. If you short the leads in the relay box for the AC clutch, it should kick on, if it does, look into replacing that pressure switch. Wheres that located at? That will probably be the first thing on my list to check. One thing I can add to the checklist: (This is assuming everything listed above checks out) Pull the electrical connector off of the AC compressor, and probe it with a voltmeter. Go in the car and switch on the AC and see if you're getting voltage to the compressor. If you're getting voltage, then I guess the compressor is shot. About how many volts should it be receiving, 12 or so? Quote Link to comment Share on other sites More sharing options...
Whiskey River Posted May 24, 2004 Report Share Posted May 24, 2004 Yours might be the pressure switch has gone bad. Mine does the same thing when it is cold out. If you short the leads in the relay box for the AC clutch, it should kick on, if it does, look into replacing that pressure switch. Wheres that located at? That will probably be the first thing on my list to check. The pressure switch on my Lumina is below the air cleaner next to both the high and low charging ports. If you are getting voltage to the compressor then you may have a bad compressor, if you don't get voltage, then short the relay and see if it is even being signaled to come on. Quote Link to comment Share on other sites More sharing options...
DiscoStudd Posted May 24, 2004 Report Share Posted May 24, 2004 About how many volts should it be receiving, 12 or so?You are correct, Sir!!! Quote Link to comment Share on other sites More sharing options...
slick Posted May 24, 2004 Report Share Posted May 24, 2004 Ok, is the pressure switch on the High pressure line, like show in this picture(its the circled one): How do i short it out? Do i just take like a piece of wire and put it between 2 of the little connectors? Quote Link to comment Share on other sites More sharing options...
Intlcutlass Posted May 24, 2004 Author Report Share Posted May 24, 2004 Wow, and i was just about to post the exact same thing. You mean you just had a kid too?? ...........J/k OK, .. Yes, my fuses are good, and I am pretty sure the relay is fine... Pressure... I don't know. What should I be looking for? Also... FYI... I know next to nothing reguarding A/C.... Quote Link to comment Share on other sites More sharing options...
Intlcutlass Posted May 24, 2004 Author Report Share Posted May 24, 2004 OK I just ran out and turned the car on, turned the ac on, and the wheel where the compressor? is... it's not spinning... Is that the same as "So, my problem is that the clutch isn't engaging. It's driving me nuts too, because i do a lot of highway driving, and can't stand to have the windows down while doing 70 mph." Is the inner wheel that I am looking at the clutch for the compressor? GM 3100 on the left.. the forward most pulley?? Quote Link to comment Share on other sites More sharing options...
slick Posted May 24, 2004 Report Share Posted May 24, 2004 Do you know where the compressor is first off? Its located at the front of the bottom of the engine on the pulley side (passenger side) of the car. There will be nice and shiny metal tubes running to it. Anyways, the clutch is part of the compressor. *I think* that it moves in and out, but im not sure. My dad popped his hood on his impala yesterday and had me hit the AC button to see what the compressor does and he could see the clutch movement in the impala, but not my car(ac compressors may be different, but i can almost guarantee the clutches will either be similar or the same). Quote Link to comment Share on other sites More sharing options...
Intlcutlass Posted May 24, 2004 Author Report Share Posted May 24, 2004 Do you know where the compressor is first off? Its located at the front of the bottom of the engine on the pulley side (passenger side) of the car. There will be nice and shiny metal tubes running to it. Anyways, the clutch is part of the compressor. *I think* that it moves in and out, but im not sure. My dad popped his hood on his impala yesterday and had me hit the AC button to see what the compressor does and he could see the clutch movement in the impala, but not my car(ac compressors may be different, but i can almost guarantee the clutches will either be similar or the same). Yep, thats what I was looking at.....pully sude.. silver cylinder with tubes going into it, and has a pulley on it.... Quote Link to comment Share on other sites More sharing options...
slick Posted May 24, 2004 Report Share Posted May 24, 2004 Yep, thats her. I couldn't tell you exactly where the clutch is, but im thinking that is kinda inside the pulley. What happens when you hit the ac button is that the clutch engages and the pulley doesn't spin freely anymore. But when you turn off your AC, the clutch will disengage (the shaft for the compressor will stop spinning), but your pulley will still be spinning because its always attached to the belt. You kinda get what im saying? Anways, i need to have my dad show me what the clutch looks like, so i can describe it to you. Quote Link to comment Share on other sites More sharing options...
Intlcutlass Posted May 24, 2004 Author Report Share Posted May 24, 2004 So from the earlier post, the plate thats inside that wheel the clutch? ,... When you turn on the ac, then that is supposed to start spinning right? Quote Link to comment Share on other sites More sharing options...
GnatGoSplat Posted May 24, 2004 Report Share Posted May 24, 2004 If you're low on freon, the clutch isn't going to kick in. Only way to tell (that I know of) is to get a manifold gauge set on it. OR start adding freon with the engine running and see if the compressor kicks in! If it does, you have a leak. If somehow you're able to determine the freon isn't low, then I agree that it's most likely a pressure switch or it could also be a faulty compressor clutch solenoid. Quote Link to comment Share on other sites More sharing options...
Intlcutlass Posted May 24, 2004 Author Report Share Posted May 24, 2004 how much pressue should there be? Quote Link to comment Share on other sites More sharing options...
slick Posted May 24, 2004 Report Share Posted May 24, 2004 Yeah, i have one of the guages and was constantly checking it. It was at 45 psi(on the box it came in, it said thats about optimum psi). It was actually a bit high after i had initially charged it, so i let out some of the pressure. I've allready checked the pressure switch. When i connected to of the little things in the plug, the car died, so im assuming thats good Quote Link to comment Share on other sites More sharing options...
Whiskey River Posted May 24, 2004 Report Share Posted May 24, 2004 how much pressue should there be? Typically, if the static pressure is below 50 or 60 psi, it won't kick on the compressor. It really should be around 100+ on a warm summer day. Once the compressor is running, your pressures should be 30-40 psi on the low side and anywhere from 180-250 on the high side. Slick94Prix: Yes, that is the pressure sensor. If it is a three wire sensor then you really can't short it out to check the compressor as it is a variable sensor, too high or low of a reading and it turns the compressor off. Quote Link to comment Share on other sites More sharing options...
slick Posted May 24, 2004 Report Share Posted May 24, 2004 Well, i checked both of them. Aparantly when i press the AC button, its not sending any power to the compressor. I had an extra car battery sitting in my garage, so i hooked it up to the compressor, and sure enough, the clutch engaged, so the compressor is not bad. So, does anyone have a good wiring diagram for me to trace the wires. All the relays and fuses are good, so it has to be a wiring problem. Quote Link to comment Share on other sites More sharing options...
95DropTop Posted May 24, 2004 Report Share Posted May 24, 2004 Another timely post...I am having a/c problems too. My 95 blows fine and gets cool, but not cold. My Mazda MPV gets ice cold, which is my comparisson. Also, when I accelerate (anything above just mild pressure on the go-pedal) the fan slows to almost no air blowing. Then when I let off, it returns to normal force. In the mini, when I get into it hard, it does not slow any discernable amount. I have seen a plug near the air box that was unplugged but I could not find where it went. I saw another post where something a/c related was located around the air box. Could that be something that causes the problem I am having? It is 90-95* out and I usually drop the top, but I cannot always and I want to make sure the a/c is working properly. Or could low R134 be causing the fan to blow less? A pic of where to pressure check would be nice! Quote Link to comment Share on other sites More sharing options...
Whiskey River Posted May 25, 2004 Report Share Posted May 25, 2004 Well, i checked both of them. Aparantly when i press the AC button, its not sending any power to the compressor. I had an extra car battery sitting in my garage, so i hooked it up to the compressor, and sure enough, the clutch engaged, so the compressor is not bad. So, does anyone have a good wiring diagram for me to trace the wires. All the relays and fuses are good, so it has to be a wiring problem. I wouldn't rule out the pressure switch just yet. What is your static pressure? It should be above 60 psi. If it is and the compressor still isn't coming on, then you have a bad pressure switch. A good set of gauges would be the thing to have right about now. Quote Link to comment Share on other sites More sharing options...
Whiskey River Posted May 25, 2004 Report Share Posted May 25, 2004 Another timely post...I am having a/c problems too. My 95 blows fine and gets cool, but not cold. My Mazda MPV gets ice cold, which is my comparisson. Also, when I accelerate (anything above just mild pressure on the go-pedal) the fan slows to almost no air blowing. Then when I let off, it returns to normal force. In the mini, when I get into it hard, it does not slow any discernable amount. I have seen a plug near the air box that was unplugged but I could not find where it went. I saw another post where something a/c related was located around the air box. Could that be something that causes the problem I am having? It is 90-95* out and I usually drop the top, but I cannot always and I want to make sure the a/c is working properly. Or could low R134 be causing the fan to blow less? A pic of where to pressure check would be nice! An AC unit that runs cool and not cold could be a number of things. The cheapest would be a low charge, for you anyway. Next thing to look into is the heater door not closing fully, allowing heat from the engine to heat the air before it gets into the cabin. You can try this, first thing in the afternoon, after the car has completely cooled, start it up and turn on the AC. If it gets ice cold and then gradually gets warmer as the car warms up, you have a sticking heater door. As for the pressure check, the valves should be under the airbox. There should be a blue cap (low pressure) and a red cap (high pressure). If those don't fix it then it starts to get quite costly. Could be a weak compressor, blocked condensor, blocked orifice tube............. Quote Link to comment Share on other sites More sharing options...
slick Posted May 25, 2004 Report Share Posted May 25, 2004 I wouldn't rule out the pressure switch just yet. What is your static pressure? It should be above 60 psi. If it is and the compressor still isn't coming on, then you have a bad pressure switch. A good set of gauges would be the thing to have right about now. What do you mean static pressure? All i know is when i hook the guage up to the low pressure side of the AC lines, it reads right where the guage says its still safe. I shorted out the pressure switch with my engine running, and the car died, so im assuming that the switch is good. But, like i said, i had the extra battery lying around and we hooked it up to the compressor, and the clutch immediately switched in, so the comressor IS good. We are really thinking its a wiring problem. Oh, forgot one thing. We had to actually let a little of the stuff out of the AC lines, because it was WAY too high. After letting some of the coolant crap out, it was in the highest part of the normal range. Quote Link to comment Share on other sites More sharing options...
Whiskey River Posted May 25, 2004 Report Share Posted May 25, 2004 I wouldn't rule out the pressure switch just yet. What is your static pressure? It should be above 60 psi. If it is and the compressor still isn't coming on, then you have a bad pressure switch. A good set of gauges would be the thing to have right about now. What do you mean static pressure? All i know is when i hook the guage up to the low pressure side of the AC lines, it reads right where the guage says its still safe. I shorted out the pressure switch with my engine running, and the car died, so im assuming that the switch is good. But, like i said, i had the extra battery lying around and we hooked it up to the compressor, and the clutch immediately switched in, so the comressor IS good. We are really thinking its a wiring problem. Oh, forgot one thing. We had to actually let a little of the stuff out of the AC lines, because it was WAY too high. After letting some of the coolant crap out, it was in the highest part of the normal range. The gauge you are referring to, is it a single gauge on a short blue hose? Does it give you any numerical pressure readings? What I am referring to when mentioning static pressure is the pressure of the system with the compressor off. Typically those single gauges are used to measure the low side pressure when the compressor is running. Unless the instructions with the gauge say otherwise, it sounds like you have a very low charge. Try this, start the engine, hook up the gauge and the short the compressor and see what the gauge tells you. Don't let it run like that too long as a low charge also means that the oil isn't getting circulated through as well as it should. Quote Link to comment Share on other sites More sharing options...
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