no cold air

Hi there,

If this vibration is only when the A/C is turned on the compressor may be failing,

Let use this guide to see whats going on

https://www.2carpros.com/articles/car-air-conditioner-not-working-or-is-weak


Please run down this guide and report back. Mark (mhpautos)

Two weeks ago my car died on the highway while driving, I thought it was alternator due to gauges going up and down and dashboards flashing. Took it to Firestone and they said it was just battery. Got car back and a/c started to blow cold then hot air. This morning while driving, I turned on defrost cold air because of storms, and my car started to run hot. I turned defrost off, and temp went back to normal. Any ideas?

check coolant level then pressure check for leaks. cold be a charging problem as well or check battery terminals for being clean and tight. or a bad body to battery ground.

Was installing a aftermarket radio and forgot to disconnect the negative terminal. Started cutting wires and shorted power to ground. I fished up with the install and the radio did not work and now my air conditioner compressor does not come on?

Check the fuses inside and under the hood. You did not say which wire you shorted. If it was for the radio's memory, that is always tied into some other circuit that is always live. Interior lights are used most commonly, but it could also be the horn, brake lights, cigarette lighter, or another computer memory circuit. The HVAC Computer could be involved.

Some radios will be totally dead if the memory 12 volts is missing. Some will only have no sound. They will light up and tune a station. Others will work perfectly fine except each time you turn them on they will reset to 12:00 or 10:00 and the station will go back to a factory preset.

Thanks for the reply. I checked all fuses and two were blown. One radio fuse and another for the transmission. After I replaced both fuses the aftermarket radio I installed works fine, but still no air conditioner. i hooked up my scanner that I have and I had a p0118 code I believe and long story short the ECT sensor came loose and stopped the air conditioner from working. lol Thank you again for the help.

Glad we can help please use 2CarPros anytime we are here to help

Best, Ken

The air conditioner on my 2003 GT is barely blowing cold air. At idle the ac compressor clutch seems to continually cycle in & out. The engine rpm's increase & decrease as this is happening. Has anyone experienced a similar issue? Any ideas on how to correct the problem.
Thanks in advance

Hi there,

The first thing you need to do is get the system pressures tested, this will give the tech a good idea as to what is going on in the system.

Mark (mhpautos)

In the morning i turned on my heater to unfog my window i turned it to full fan and i was about to turn off when it just turned off its self and i tryed the ac and didnt want to work either but when i turn on it makes a noise like relieving pressure and we checked everything and cant seem to find the problem.

Check the blower motor fuse. If good, check for power at the blower motor itself with the ignition ON and the blower speed setting on HIGH.

the a/c will blow cold air when the car is stopped, but will blow warm air when im driving it, what could this be?

An A/C system that blows cold air for awhile then warm air is probably freezing up. This can be caused by air and moisture in the system that allows ice to form and block the orifice tube.

Evacuating the system with a vacuum pump will purge it of unwanted air and moisture. Evacuation should be done with a vacuum pump that is capable of achieving and holding a high vacuum (29 inches) for at least 30 to 45 minutes.

For best performance, an A/C system should contain less than 2% air by weight. For every 1% increase in the amount of air that displaces refrigerant in the system, there will be a corresponding drop of about one degree in cooling performance. More than 6% air can cause a very noticeable drop in cooling performance, and possibly cause evaporator freeze-up.

Air can get inside a system through leaks, by not evacuating the system prior to recharging it, and/or by recharging the system with refrigerant that is contaminated with air. Recovery equipment can suck air into the recycling tank if an A/C system contains air or if the system has a leak. For this reason, the refrigerant recovery tank on recycling equipment must be checked and purged daily. On some equipment, this is done automatically. But on equipment that lacks an automatic purge cycle, tank pressure and temperature has to be measured and compared to a static pressure reference chart.

Some refrigerant identifier equipment can detect air in the system as well as other contaminants. An identifier should be used to check the refrigerant before the system is serviced to prevent cross-contamination of recovery and recycling equipment.

Possible causes of intermittent cooling in a manual A/C system that might be caused by an electrical problem include:

Faulty low pressure cutout switch. This switch prevents the compressor from running if the refrigerant level is low. If the cutout switch is not reading correctly, it can prevent the compressor from coming on.

Faulty compressor clutch. The magnetic clutch on the compressor requires full battery voltage to engage. If the voltage to the clutch is low, or the clutch coils have too much resistance, or the air gap in the clutch is too great, the clutch may not engage to drive the compressor.

Faulty compressor clutch relay. Check to see if the relay is receiving voltage when the A/C is turned on. Also check the relay wiring and ground connections. If bypassing the relay with a jumper wire or routing battery voltage directly to the compressor clutch makes the A/C work, the relay is probably bad.

Faulty A/C control switch. The switch may be worn and not making good contact when it is turned on.

Some possible causes of intermittent cooling (or no cooling) on automatic A/C systems include all of the above, plus:

A problem in the control module or control head (this usually requires using a dealer scan tool to read fault codes and perform self-diagnostics).

A bad temperature sensor (an ambient air temperature sensor, interior air temperature sensor, evaporator temperature sensor, or sunload sensor). Again, a factory scan tool is usually required to perform diagnostics on the system.

2002 Ford Mustang V8 Two Wheel Drive Manual

Hello all,

I recently installed an a/c eliminator kit and now my car won't start.

I removed the hose and two wires that fed into the compressor, and rewired the remaining wires back where they belong. I honestly have no idea why it isn't starting.

FYI, I installed a 93 octane performance tune previous to the a/c eliminator kit installation, but even after the tune it would still start. Don't know if this has anything to do with it or not.

The car was starting fine before the installation of the a/c eliminator kit, but now it is just turning without fire. Any ideas?

Instincts tell me it's just coincidence it won't start. The ac modification should have nothing to do with it unless you unplugged something you're unaware of.
You need to check to see what is missing. Spark, fuel pressure or injector pulse. Or, any combination of the three. Also, check the connection on the crankshaft position sensor. Please advise.

James,

Thanks for the response...here's the update:

I checked for spark and I'm getting it to light up on the right side when facing the engine, but the entire left side isn't getting any juice.

The wires that came from the left wiring harness, and to the a/c compressor plug into the block at the bottom left. Only two wires from this group went to the compressor, and I sealed those two wires off with electrical tape, and the other two wires are plugged back in. The connection though isn't snapping on because I broke the clip that holds it on tight, though I held it in tight when my brother tries to start it, and we still get no fire.

I'm getting fuel pressure, not sure how to check for the injector pulse, and am getting spark only on the right side of the engine. I'm not sure where to find the crankshaft sensor, I'll have to look that up.

Ok, so I went to the salvage yard and got the wires with the connector, wired it up, plugged it in, and it fired up!

Turns out it was the connection on the bottom of the block that was preventing it from starting.

Thanks

Ya' done good. Anything else, you know where to find us.

My wife drives a 200o Ford Mustang 3.8L V6 and the A/C stopped working. We have changed the mass airflow sensor, I've put a new compressor on, checked the freon level and checked all fuses. Nothing has fixed the problem. The compressor is getting 12 volts but it's not kicking on. The CCRM is getting power too.
I don't know what to do next, please help.
Thanks for your input.

Hi ossiv99. Welcome to the forum. If you have 12 volts to the compressor, that just leaves ground and the clutch coil. I can't remember for certain, but I believe the coil is always grounded and the 12 volts switches on through a relay. That's the way most cars are wired. If that's the case, check the resistance to ground on the coil's ground wire and measure the continuity of the coil. One of those two has to be open.

To not overlook something stupid, did you measure the 12 volts with a voltmeter or a test light? If you used a voltmeter AND the connector was not plugged into the compressor, the results can be misleading. The voltmeter will not draw a significant amount of current, so pitted relay contacts that can't pass enough current to run the compressor clutch, will still allow the 12 volts to be seen by a voltmeter. A test light draws much higher current and will cause pitted contacts to show up as low or missing voltage to the coil. For older cars that used special wires for fusible links, the same thing can happen when the wire burns open and leaves a carbon track behind. No current will get to the clutch coil, but voltage will be measured by the voltmeter when the connector is unplugged.

caradiodoc

I've checked voltage, there is 12volts w/ no amps
coil is good and engages when I jump it straight from battery
There are good wires to all sensors voltage & continuity is good on all sensors
I did a backprobe on the CCRM connector and got voltage on terminal 21 but not 22 or 23
According to some online diagnostics I was reading, that means the CCRM is bad.
Does this sound correct to you?
Thanks for your help.

Sorry for letting you sit. My Verizon e-mail is going through major changes, (none of them for the better), and sometimes it goes down for an entire day, then I don't get the automated messages directing me to your reply.

How are you jumping the compressor to make it run? Do you just need the posiitve wire, or do you have to connect a ground wire too?

The most accurate way to measure the voltage on the clutch coil is with it plugged in. When it should be turning on, measure the voltage between ground and the 12 volt wire, then between ground and the ground wire in the plug. If you have 12 volts on the ground wire, that ground wire is the circuit that needs to be looked at.

caradiodoc

I just changed the brake pads on my 2000 Mustang GT, along with the brake fluid. After driving to set the brakes, the brakes were EXTREMELY hot and remained that way for quite some time. Even with the gel put on the brakes, the pads were literally smoking after a short 10-mile drive. A few days later I took the car out for a drive through the country with little braking and when I got home I could smell the brakes (I could towards the end of the drive also). The brakes and callipers remained hot to the touch for nearly an hour after the short drive (less than 30 minutes with minimal braking). I cannot feel the brakes rubbing as I drive but they obviously are. Any reasons why they would be doing this? Do they need a break in time? Did I forget to do something when I changed them? I did re-set the callipers with a C-Clamp but have read that some of the Fords need to turn the callipers. Were the 2000 Mustang GT's like this?

Thank you for your help,

Nolan

Hi Runnikee. I think your last comment might be the key. You should never HAVE to use a c-clamp to push the pistons in. If a ring of dirt or rust has built up around the pistons, they wil stick on the seals and won't release properly.

Try stopping on a slight incline to see if the car will creep ahead on its own in neutral when you release the brake. If it does not, crack open the steel lines at the master cylinder and see if they release. (You might want to put a block of wood in front of one tire so you don't look funny chasing your car down the hill, like happened to me once). If that doesn't help, try opening the bleeder screws on the calipers. (No block of wood needed. The car will stop when it tries to run you over! :)). If that doesn't help, the calipers will have to be replaced or rebuilt. In the '80s, we rebuilt calipers with every brake job, but today professionally rebuilt calipers with a warranty are so inexpensive, it doesn't pay to do it yourself unless you're "emotionally involved" with them and want to keep the original parts.

The calipers are most suspect since the problem started when the pistons were pressed in to make room for the new, thicker pads. If, however, you had to replace the pads because the brakes were staying applied, cracking open the hydraulic system at the master cylinder or bleeder screws will point towards a constricted hose, (unlikely to have two at once), or brake fluid contamination.

caradiodoc

How do you compress the pistons back until they are fully seated without using a C-clamp? If you don't do that, how are you going to get the new pads back over the rotor? I've read some of these pistons need to be twisted with a special tool as opposed to being simply pushed down. Do you know if this is the case with the 2000 Mustang GT?

Thanks again for your help and quick reply.

I like to pry the pistons in with a flat blade screwdriver before I unbolt the calipers. If they don't go in that way, there is a restriction in the hydraulic system or the pistons are sticking. Open the bleeder screw. If the piston goes in now, the hose could be constricted or the brake fluid is contaminated with petroleum product.

Hose constriction is more common on Chrysler products that use a metal anchor bracket in the middle of the rubber hose. Rust buildup inside where that bracket is crimped around the hose pinches it off. The brake will apply with heavy pedal pressure but will take a long time to release, (potentially hours). The pedal will be higher and harder than normal too. The fix is real easy and just involves using a large pliers to open the crimp a little. Another hint is the brake won't release when cracking open the line at the master cylinder.

If the piston will pry back after cracking the steel line at the master cylinder, fluid contamination should be suspected. Petroleum products, such as power steering fluid, engine oil, and transmission fluid causes rubber parts to swell. The clue is the bladder seal under the reservoir cap will be greatly expanded and mushy. The lip seals in the master cylinder also grow past the return ports and trap the fluid. As the brakes heat up, the heat transfers into the fluid which expands and since it can't flow back into the reservoir, it applies the brakes harder.

On Fords, it's more common to simply have rust pits or dirt on the pistons causing them to stick. You will not be able to pry them back even with the bleeder screw open. The c-clamp will get the piston to go in, but that rust or dirt will be under the square-cut seal. The way the seal is supposed to work is it tends to stick to the piston when fluid pushes the piston out to apply the brake. By sticking to it, it deforms or bends a little. When you release the pedal, the seal wants to straighten out. That's what pulls the piston in just enough to release pressure on the pads. As the pads wear down, the piston moves out a little further. The seal can only bend so far, so the piston slides a little through it. That's how it self-adjusts. When dirt or rust is on the piston, it will stick applied and refuse to release.

As for screwing the pistons in, that only applies to GMs and Fords with the parking brake built into the rear calipers. Once they are screwed in and the pads are installed, they will only come out by applying the parking brake. Regular use of the parking brake is required to keep the rear calipers in adjustment. Chryslers have always used a drum parking brake inside the rotors when the rear uses disc brakes. Some newer Fords are going that way too. It is a much simpler and more reliable design.

caradiodoc

Thank you very much for all of your help and the great information. Hopefully I'll have time this week to open it up again and look for restrictions to solve the issue.

I drove my car home and parked it for 30 mins, the air had been working fine. I got in and started it up, and the air wouldnt blow cold. I checked and the A/C clutch wasnt enaging. I jumped the low pressure switch, and the only thing it did was raise the engine RPM. Removed the jumper and the RPM lowered. Checked the system and its at the proper pressure. So I used a meter and checked the connector going to the compressor. I am getting 13 volts to the connector when the a/c is turned on. However, when I plug the connector in, the clutch does not engage. So I jumped the compressor to the battery.... the clutch engages and the car blows cold air. So, I have 13 volts at the connector, no clutch engagement and if I provide power from the battery then the clutch engages. If I run leads from the connector to the compressor, it wont engage. So now I am lost. Oh, when I run the leads from the connector to the compressor, it seems to be pulling .5 amps, when I run the leads from the compressor to the battery, it seems to be pulling 4 amps.

I appreciate any help you guys can offer!

Thanks.

Ok I need you to do some testing. You will need a digital multi meter for these tests. First you will unplug the A/C cycling switch and then check the ohms of resistence between the violet wire and ground. Then with the a/c selector in the a/c position check the high pressure switch unplug the harness there and check the ohms between the dark blue wire with yellow stripe and ground too. Lets start there and see what we find. Thanks

Thank you for using 2CarPros.com. We appreciate your donation and look forward to helping you in the future.

Sorry for the delay in replying. I am not great at auto electrical, so here's what I found.

I disconnected the cycle switch and checked it and got a reading of 1 with the a/c off. When I turned the a/c switch to on, I got a reading of 374.

Not sure where the other switch is, but I am guessing its the connector to the compressor, as it had a ground wire and an dark blue with yellow stripe wire. From there it was 3 ohms with the a/c turned on. Hope that is what you needed, please let me know. I appreciate your help, its getting so hot out here!

Thanks

OK so far so good. Now there should be a violet wire at the A/C compressor switch. I need you to unplug that and check the resistance between the violet wire and ground should be 10k ohms or more if it is less then that then you need to check that wire for any breaks or shorts. If it is more then 10k ohm then you need to do the next step.
Plug the switch back in and back probe the violet wire with a paper clip and connect your meter between that and ground and then you will need to set it where you can see it from inside the car and then rotate the selector switch and put it in all possitions. If any possition is less then 10k ohms during this then the selector switch is no good. If all is good here then get back back to me and we will go to the next step. You are welcome I am a Ford and Mustang guy myselft. I also have a 98 Mustang V-6 with many mods and for summer and a 95 F-150 for winter. Glad to try to help. Let me know what you find.

Ok, I hope I tested at the right point. I disconnected the cycle switch plug (the one you jump to see if the low side switch is bad). I put the meter on 20k ohms and put the red lead to the purple wire and the black lead directly to the negative side of the battery. For the most part the meter just read 1 or changed to -1 when the selector inside was turned from off to normal a/c or to max a/c. If I moved the black lead some, sometimes it would give more numbers, but nothing consistent.

The part of this that is really killing me is that if I provide positive power from the batter and ground from the clip into the compressor it kicks right on. However, I get voltage at the clip of 14 volts but it wont turn the compressor on.

This problem really has me hitting my head! Again, I appreciate your help and will gladly donate more when we get this fixed!

Thanks!

OK no worries we will get this it just takes a bit longer to do this over the net as apposed to having the car infront of me. Now what I would like you to do is first check the a few fuses. Fuse number 2, 23 , 24, they should be a 20 amp, 15amp and 30 amp in that order, these are in the fuse box inside the car. I also need you to check the black wire with the yellow stipe at the a/c clutch. This is the power wire to the clutch coils and with the car on and the a/c on max do you get power there? If not then you need to find the A/C relay in the relay box behind the engine coolant reservior and check that the red wire is getting power to the relay. If that is good then check the dark green wire with the orange stripe at the relay to see if it has power. If this don't have power then I need you to check the fuse in the junction box that is infront of the drivers strut tower. It is the 20 amp fuse for the a/c relay, make sure it is good. I know this is a lot to check and if you have any problems please just ask. Let me know what you find here.

What is causing my Ford Mustang to start running hot?
It also will blow cool air when you have the heat going sometime?

I have replaced the thermostat, I have checked the hoses, there is water in the reservoir and the radiotor.

What should I do next to fix the problem?

Ok, I checked the fuses and they are good. I also checked the wire going to the a/c clutch and am getting 14 volts there, so do I need to check the other wires you listed since it has voltage? I completely understand the time it takes over the internet and truly appreciate the help.

Is it really running hot or is the temp sending unit not working. If you can have it checked with an inferred heat gun to see if its running normal temp or not first and we can go from there.

Ok no if you would unplug the ac clutch and check resistance across the terms of the clutch. Get back to me with what you find. So far sounds like a bad clutch coil. Thanks

Well its raining right now, so I'll have to check that tomorrow.

If it was a clutch coil, why would it turn on when I run power directly from the battery and ground from the connector? Just asking, as I am not good with electrical, but thought it made sense.

As for checking resistance across, put one lead to each end of the connector and check the ohms, right?

Sorry your right some times I forget to read back to make sure where we are at. With that I need you to find the A/C clutch relay and the EDF relay next to it. These are in the relay box behind the coolant resersior. I am thinking that one of these are getting overheated and shutting down there for needing replacement. Everything else you tested checks out good so far so that is the only thing that makes sense. Once you find them then I need you to check to see if the pink wire with the yellow stripe to the ac relay get power when you turn it to ac. Then check to see if the EDF control relay get power from the dk blue wire. Let me know what you find.