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Climate Control Problems (Air Conditioning, Heat) - All Cars



  • Mr_ShiftrightMr_Shiftright CaliforniaPosts: 56,730
    That's probably are getting de-humidified heat through the a/c system.

    The only other "plain water" in a car might come from the windshield washer reservoir.

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  • After 45 min of using heater or A/C nothing will come out of any vent. Blower still works. Turn it off (turn the fan swich to "off")for 5 min and it will return to normal when switched on again. Have replaced air door actuator, control panel and A/C solenoid. Still have the problem. (It does seem like a tired solenoid, though) Could it be the BCM (body control module). Where is this? Is it next to the underhood fuse box? No other part of the cars' functioning is affected.
  • desi501desi501 Posts: 66
    Could be a lot of things but kinda sounds like the evaporator is freezing into a block of ice and not allowing air to flow through. I believe that system uses either a thermostat or a cycling switch to control that. Some one needs to look at a schematic to determine what component should be doing the cycling. Make sure no one has "jumped out" any switches to make it colder.
  • As I said, the problem is the same when using the heater as well - not just an A/C problem. Thanks for replying.
  • desi501desi501 Posts: 66
    Just because your using the heater doesn't mean the A/C compressor is not running, in fact more and more vehicles are wired to run with the compressor these days to remove humidity especially in defrost mode. Like I said, next time look at the compressor. It will only take a second and you can eliminate the possibility and look elsewhere. Believe me, it IS possible.
  • I willpay attention to this possibility, thanks again
  • Mr_ShiftrightMr_Shiftright CaliforniaPosts: 56,730
    I think you could get along fine without air in upstate NY, but it will have some effect on resale value nonetheless.

    Whatever allows you to buy a car at a good price will haunt you when you go to sell it.

    I agree, most aftermarket A/C is of questionable engineering.

    If you could get the dealer to install factory air, I think you'd get back most of your money at resale time---I know you can get a/c put into a Civic for around $1,000-1,200, so if it's in that price range, it might be okay. I wouldn't spend much more, though.

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  • wwestwwest Posts: 10,706
    Search for "wintertime a/c tips" and "windshield fog" in discussions.

    And have a look at:
  • Every year when it get's to around -30 outside, the blower motor stops working. This is my mom's car, and I've never worked on it before. But everytime she has taken it in, they replace part# F4DZ-19980A. It's supposedly a heater control unit. Where abouts is the location of this unit? I've checked all the fuse and relays, there is power on both sides, as well as power at the A/C switch. However there is no power on any of the contacts, of the fan speed switch.
  • alcanalcan Posts: 2,550
    Manual or automatic AC?
  • Automatic with A/C
  • andys120andys120 Loudon NHPosts: 18,388
    is a failure to communicate".

    -from Cool Hand Luke

    I think Alcan wants to know if you have the computer-controlled Automatc Climate Control or do you manually switch on and adjust the a/c, not the transmission.

    2000 BMW 528i, 2001 BMW 330CiC

  • alcanalcan Posts: 2,550
    Yep. Does the heater/AC control head have 3 round knobs, or a series of pushbuttons?
  • nybill38nybill38 Posts: 12

    I have a 1990 Mitsubishi Sigma, the compressor would run but I would get no cold air, I bought a conversion kit to R134A and the guage said there was a little R12 left but now the compressor clutch won't engage, the compressor is still running...when I turn the A/C on there is now no drag on the engine and the rad. fan doesn't come on like it did before I started this process. Could the thing not be running since there is no freon in it....if thats the case how can I get the new freon in it, since the directions say for it to be running??? HELP

  • swschradswschrad Posts: 2,171
    that is, the refrigerant oil that was in the R12 system. I have seen in many places that the viscosity of the R12-grade oil goes way up under R134a usage (that is, it turns to very heavy sludge) and you have a blockage in the piping. that is unbalancing the pressures in the system, and one of several protection switches is preventing the compressor clutch from engaging.

    you could also have blown a clutch fuse, but you would run into the thick-oil issue as well.

    generally speaking, since I don't have the EPA training and the new equipment I must speak generally here, you would have to drain oil from a low spot and/or replace the dessicant/dryer pad and blow the old oil out with dry nitrogen, then add the appropriate amount of lighter R134a-compliant oil to the system using a charging station during vacuum evacuation of the system. that would distribute the oil generally where it belongs. you then recharge with R134a and test.

    I always thought something was missing from the little boxed R134a kits, like a Gould vacuum station....
  • Mr_ShiftrightMr_Shiftright CaliforniaPosts: 56,730
    If there's not enough refrigerant, the compressor will not engage, that's correct. There is a coupling you can separate and then by-pass this safety system temporarily with a jumper wire, but I'm not gonna tell you to do that.

    I agree, spend $150 and get a pro hook-up to test this system.

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  • virgiesmomvirgiesmom Posts: 59
    I have a 92 Mustang conv, 4 cyl. Air conditioner was converted to R134 last summer. I need to return to service since not producing cooling air.
    Last year we were told by service tech that as long as the temp of the air at the vent was a delta of 40 degrees from ambient then within spec (barely that last year).
    I remember prior to conversion the temp could get to 37 degrees with ambient at 90. Work has been done by Linc-Merc dealer. What should I measure?
    Wife is very disappointed
  • swschradswschrad Posts: 2,171
    R134a is not as efficient as freon-11 was. a delta of 40 is probably about right. use a probe thermometer in the center vent, air on max or set to cooling, panel airflow, all the way cold on the knob, and fan switch on highest setting, whichever fits your control panel. if it's humid and/or above 80, you should have a big old fan helping the one on your engine keep things cool, set your biggest fan in front of the radiator and blow full tilt through it.

    under those conditions in idle after a few minutes, you should see a temp reduction of about 35-40 degrees. if so, you have no air conditioning problem, just fond memories of the old ice-chunk-thrower a/c systems that are gone for ever more.

    things you can do to help your cause are

    1) use the reflective window blockers when parked

    2) leave a window or two cracked when parked if the local crime statistics permit it.

    3) when getting in the car and starting it, zip down a couple windows and fire up the fan for a couple minutes full-blast to knock as much of the hot air out of the car as possible before closing up and driving off.

    4) if at all possible, dress for the weather to get additional aid against the heat. it would be better to wear shorter and light-fabric outfits in summer, of course. any job requiring a dark knit suit is IMHO not worth taking, anyway ;) but some do it and moan about the air conditioner.

    5) there is always the R255 or R455 air conditioning systems, if all else fails. they are: roll down 2 or 4 windows, whatever you have, and do 55.

    there is a reason you don't see black interiors any more, and it is spelled R134a.
  • robblesrobbles Posts: 4
    My son has a 1991 Toyota Celica GT. He just spent $140.00 to have the A/C converted to the new stuff. Worked like an igloo the first day, and went downhill from there. It's more than likely a bad leak, which means he'll have to spend more money to have it charged with red dye to find the source of the leak. Then hopefully will have a good diagnosis for next steps, along with costs.

    The car has 108,000 miles on it. He just spent money on front brakes, and has new tires with 6,000 or so miles on them. Money is an issue. He has had the car for three plus years without A/C. So, does he eat the $140, or seek out the diagnosis? Any history on what others have spent on A/C leaks? He still loves the car, and it is in great shape.
  • andys120andys120 Loudon NHPosts: 18,388
    and my R-134A system is doing a fine job of keeping the car cool, in spite of the black leather interior.

    2000 BMW 528i, 2001 BMW 330CiC

  • swschradswschrad Posts: 2,171
    R255 is, of course, the old-time coolant.. Roll down 2, and do 55.

    he's likely got a bad hose, and it's going to take a dye-and-refill cycle to find it. not uncommon to have a system with several problems at once, especially when it's been down for a few years and you try and bring it up.

    I'd expect the refill and replacement hose, if that's what the problem is, to end up costing over $200 and under $400. there are a lot of factors at work here, including whether it's a solid hose with a creepy end, in which case they might be able to use an adapter fitting, chop the hose back an inch or so from the failure, and recrimp to the adapter. I've had that done, and it worked well, because the techs knew what they were doing. joe maybe doing this for the first time would be better off replacing the whole hose.
  • Mr_ShiftrightMr_Shiftright CaliforniaPosts: 56,730
    System should have been leak tested during the recharge. Sloppy work I think.

    Also R134a is very sensitive to pressures. It could be that he doesn't have a leak but that the system was not properly charged.

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  • Mr_ShiftrightMr_Shiftright CaliforniaPosts: 56,730
    System should have been leak tested during the recharge. Sloppy work I think.

    Also R134a is very sensitive to pressures. It could be that he doesn't have a leak but that the system was not properly charged.

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  • burdawgburdawg Posts: 1,524
    R134 operates at higher pressure than R12. Doing these conversions from R12 to R134 is hit or miss when dealing with old components, with seals that are acceptable with R12 pressures but will fail at the higher R134 pressure. Plus, an R134 system has to work a little harder for the same results. For $140 I'm not sure you can get a good conversion done.
  • alcanalcan Posts: 2,550
    Add to that the fact that R-134a molecules are about 1/6 the size of R-12, and it'll leak from places that R-12 didn't. That's why a lot of conversions don't hold a charge and why R-134a specific hoses have a barrier liner.
  • robblesrobbles Posts: 4
    Thanks for the information on the Celica A/C conversion dilema. Now we are armed with some knowledgeable information to go back to them with. We'll keep you posted.
  • dhoffdhoff Posts: 282
    I have a 94 Mazda 626 with a 143a system. I bought it used two years ago, cheap, with 79,000 miles on it. Then the air worked great, really cold. Last summer, it was not quite as cold, but OK. Now it's working, but not too well. I figure it's got a really small leak.

    I don't want to spend a lot of money on the thing, I figure on getting a new car in a year or so, but I'd like cold air for the summer.

    I have been tempted to buy one of those little spray cans of 134a refrigerant from the auto parts store and attempting to put some in. For 15 bucks do I have anything to lose by trying this?

  • swschradswschrad Posts: 2,171
    there is a very serious and real difference between the HIGH pressure side of air conditioning and the LOW side. be aware of that. connecting a CSK or K-mart R134a kit to the HIGH side is like pulling the pin on a grenade and sliding up your face within a foot of it.

    so, if you can very clearly differentiate between the LOW (good, suction, service) port of the system and the HIGH (measurement only, pressure, killer, evil wicked mean and nasty side) port, you could try it.

    if you can't, you are better off taking this to a tech who CAN tell the difference, and wants to live to cash his paychecks.


    with that caveat... if you know what you're up to, have goggles and gloves, and a kit with a gauge, have fun.
  • Mr_ShiftrightMr_Shiftright CaliforniaPosts: 56,730
    Getting cold air isn't just about "refrigerant". You could have a bad dryer or expansion valve, too. Generally A/C is not considered a consumer serviceable item. Also 134a needs very precise pressures to work properly. You have to be right on the money.

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