Diagnostic Machine Tools

How To Diagnose Car A/C Problems

It is standard for cars of today to have an air conditioning system in them. Many times, despite the A/C being a standard, looking into this system is often neglected, especially when sent out for routine repair. You may also be guilty of the same thing because you fail to look into any issue that has been developing in your car’s A/C system. Here is how you can diagnose car A/C problems correctly.

Air Conditioning Fails to Cool the Air Effectively

Was there ever a time when you have set the A/C to maximum cool with the fans set on high but you noticed that the air blown out is not as cold as it was before? When this happens, the best thing to do is to check the cooling fans. Make sure that the condenser is running while the A/C is turned on. You must also check whether there are leaves, dirt or debris that may prevent the air from moving forward to the condenser.

You must also make it a point that the cabin air filter is not clogged. If you have a manifold gauge set, you can use that to check the pressure in the A/C. Check how much pressure there should be on the low-side and high-side by browsing through the manual.

Start Diagnosing the Issue with the Compressor

This is very important because it is in the compressor where the refrigerant gas is transformed to make the car cool. Turn on the A/C on and set it to maximum cool. Set the fans to high as well and then check whether the clutch is actually doing its task of engaging on the compressor. The clutch is the centerpiece that is used to engage the pulley to the A/C compressor’s shaft. Once you notice that the clutch engages and disengages quickly, you need to refill the refrigerant as it may be low.

Using a voltmeter, you must check how much voltage is getting in to the compressor. This must be done when the clutch is disengaged. Once you have seen that there is voltage then the clutch needs to be replaced. In case there is no voltage after using the voltmeter then it is the cycling switch which is causing the problem.

Leaks in the A/C System

A low pressure in the A/C system is an indication of a leak. There is a specific type of kit that can be used for leak detection. Make sure that when you use this one, you have to follow the instructions to the letter. Make sure that the fittings are secure and find any hose manifolds in the A/C compressor. Check everything from the o-rings and front seal to the hoses, condenser pin holes, and Schrader Valves. Take note that the dye check is not recommended if the compressor is not cycling or if the system is too low.