Is the misty air coming out of my A/C dangerous? June 21, 2006   Subscribe Had the same problem on my 2002 corolla it's the sparks or/and the coils. I recommend replacing all the sparks first sick there only in the 3-8 dollar price range. then the coils they are like 107 dollars a piece. This sounds like and electrical problem. If your engine is bogging down and you are still getting enough cool air from the A/Con system, then the A/C system will have a full charge of gas and will not need servicing. If this is the case, run the engine, with A/C on, at night and open the hood. As the A/C runs via both belt (for the compressor) and electrical (for the car system), you may see that all or some (even one) of the spark plug leads are flashing. This means that the insulation around the lead has broken down, and the electricity required to run the total power needs of the car with the A/C on will be low. If this is the case, replace the faulty lead (I would recommend replacing all), as this will allow the electrics to run at full capacity.

Another way to test the electrics is to remove the lead from each plug one at a time (with insulated pliers lest you get an electric shock), and hold the lead very close to the body of the engine. If the lead is working, there will be an electric discharge between the lead and the motor (this is not dangerous). If when removing the lead, the engine does not bog down, then the spark plug is faulty. Remember that the spark plug is only used for firing the petrol (gas) to pump the cylinders, and the electrical signal comes from the alternator, via the coil and lead to the spark plug. A vehicle electrical system works by the battery exciting the alternator, which then runs the electrical power to the coil and so on. If either the battery or the alternator are faulty, the vehicle will be running under power from an electrical point of view, so anything that requires high levels of electricity (such as the A/C) will bog the engine down. The engine bogging down is a good signal to say that the alternator is working, as it tries to ramp up the current.

If there is a high drain electrical fault (i.e. leads, coil, etc), the engine will bog down more than usual, and the interior lights will dim, as well as the headlights, as the alternator tries to source more current. If the fault is due to a loose compressor belt, the engine would not bog down, and the A/C would not get fully cool, or you could hear a squealing sound, which is the belt slipping. If none of the above are the problem, then look at the top of the A/C gas cylinder (next to the compressor - usually silver) and there will be a yellow glass bubble. If this has any air in it (it will look like a bubble), then the A/C unit needs a gas charge. This will also cause the engine to bog, as the alternator is trying to run a low pressure system (due to low refridgerant) at it's normal gas pressure, therefore requiring more current. If this is the case, there would also be a slight leak in the system, as refrigerated A/C systems are closed loop systems, and do not lose gas (this is why your fridge will still work well after 20 years).

Is your A/C cooling in the car effective? you need to check if the A/C comressor is turning freely without undue "clunkiness"drop ceiling ac diffuser Have you engine off and perform this check carefully inspecting for damage and mis alignmentsterling auto repair tampa fl self repair from this point on is unlikelybmw e36 ac control module seek assistance from a licenced Automotive A/C repairer if the compressor appears defective It is unlawful to discharge A/C refrigerant gas into the atmosphere have you cleaned the intake manifold? Just wear gloves, mask and protective eye wear, take off the large hose, and wipe the inside with carb cleaner, performing the process several times, till clean. Could be something simple as dirt on air sensor, take out air filter, and the box it sits in, you will see i little sensor inside, if there is dirt and plague on it, clean with brake cleaner.

ImperialCrown wrote about the common problem of having cold air coming from one vent and hot air from another: For other auto air conditioning solutions, click here. This article briefly describes the control system of computer controlled air conditioning systems which are typical of Chrysler vehicles which do not have automatic temperature control. This system is also similar to that of other manufacturers' products. The following components are used: 1). An electromagnetic a/c clutch. 2). The fan relay (the relay is a double-pole-single-throw type; 1/2 is used for fan control whereas the other 1/2 is used in the relay logic circuit used to control the a/c clutch). 3). The wide-open throttle (WOT) cutout relay. 4). The pressure cycling switch. 5). The switches used to select air conditioning: defrost and a/c. The point marked "to ecm" is drawn to a positive value via a pull up resistor on the computer's board. The pressure cycling switch is used to prevent ice formation on the evaporator's core (this would obstruct air flow and cause system overheating).

The WOT cutout relay is a normally closed one; it is energized (opened) by the ecm if the ecm detects a WOT condition -- this reduces engine load during high power demand. The fan relay is energized by the computer when cooling is required, a/c is required, and, under appropriate conditions, for radiator demisting (to reduce steaming when the vehicle's engine is on, but the vehicle is not moving). The clutch is an electromagnetically controlled "brake" which is attracted to the compressor when current is supplied; the friction material ensures that, if the clutch is working properly, the compressor will fully engage. The surge suppressor on Chrysler products is often a pair of zener diodes mounted back-to-back in the (polarized) connector going to the clutch. Operation of the system is as follows (assume that the car is not near WOT): The compressor is now on. The compressor will continue to be on unless WOT is reached or the pressure cycling switch opens. The process then repeats.

The following readings were taken using an OTC 500 meter and OTC current measuring clamp; they are off of a 1986 Le Baron: A common failure is the fan switch's resistance increasing. Indeed, these switches are known to melt from overheating. On 1980s products, this switch is a replaceable item (about $18) -- the entire pushbutton assembly does not require replacing. Here are some problems I ran across in my Le Baron: 1). BAD FAN SWITCH The switch didn't overheat, but caused an insufficient current to be delivered to the clutch. This caused the clutch friction material to overheat, which caused the clutch to float on a layer of gas. The symptoms were (1) gradual reduction in cold air delivery and (2) smoking refrigerant oil (leaking from a 9 years old compressor front seal). 2). BAD PRESSURE CYCLING SWITCH AND CONNECTIONS The pressure switch had bad intermittent connections; also the terminals in the external connector were corroded. The symptom was the a/c cycling on and off about three times per second (recall that the computer's timer is set to something between 300 and 400 ms).

Copious use of television tuner cleaner and polishing the blade terminals on the switch would temporarily eliminate the problem. The fix consisted of replacing the switch (aftermarket bought from a parts jobber -- about $30), replacing the terminals in the connector (available in any hardware store), and spraying the connectors' boot with silicone lubricant (for a weatherproof seal). The original terminals were merely crimped; I crimped and then soldered the connections. You will require the factory manuals (or equivalent information) and a high impedance multimeter. If a digital meter is used, it must have a bar graph display since the digital display with the dual-slope integrating analog to digital converter will react too slowly to changes in the circuit. A min/max function is also useful to have. The voltage drop from the clutch to the battery's negative terminal MUST be low when full operating current is seen -- about 700 mv maximum is ok. In my case, after all repairs were made, the voltage was between 400 and 500 mv.

For one test, I disconnected the clutch and replaced it with an unpowered test light -- this allowed me to check voltage drops with the a/c always on (pressure cycling switch would never open). Although full current was never approached (the light draws only about 300 ma), I did find bad connections. Measuring individual voltage drops is the ONLY reasonable approach. Once problems are found, resistance measurements can be used to home in on target components. For example, I found bad electrical contacts by isolating the problem to the pressure cycling switch, then turning off the engine, disconnecting the WOT cutout relay connector, and measuring resistance from the battery's negative post to the WOT connector. Moving the terminals on pressure cycling switch's connector showed a huge decrease in resistance. Television tuner cleaner didn't reduce the resistance too much, so the terminals were replaced. Ed Hennessy said one problem with 1980s Chrysler a/c systems is leaky hose fittings, which leave a tell-tale slimy residue near the metal fittings at the rubber hose connections.