How To Identify A Bad Clutch Coil In Your A/C System?

Your car’s A/C system is made up of several different components that work together to deliver cool, breathable air into the passenger cabin. The clutch for instance, drives the compressor. It also sends refrigerant to the evaporator where the refrigerant gets condensed before it is cooled by the radiator. The refrigerant, the condenser and the compressor are all very important. One minor glitch on any of these components and you will end up with an overcharged system; a glitch that is most common symptom is hot air coming from the A/C system. But just how do you identify a problem such as a bad clutch? Here is how to go about it.

Inspect Your Battery

Shift your car into park or neutral, engage the emergency brake and raise the hood. Put the positive lead of a voltmeter to the positive side of the battery terminal and the negative lead on the negative terminal. Switch the voltmeter gauge scale to volts then read the number; any voltage below 12.5 means that the compressor will not turn on. You will therefore, have to charge the battery. Replace the battery if you still get a low reading after recharging the battery as this means the battery has a shorted cell.

Examine The Clutch

Start the engine and let it run for some time so as to warm up the A/C system. Then stand in front of the A/C compressor near the engine. Have someone assist you to turn the A/C controls to their maximum. Wait for the A/C clutch near the compressor body to engage and allow it to spin. If it fails to engage and spin, shut the engine off and disconnect the battery cable with a socket.

Inspect The Fuse Box

Find the main fuse box then pull out the A/C fuse. Examine the filament inside the fuse box to find out if has been blown apart or if it has melted. Replace the filament if you have to. Swap the A/C relay the fuse box with another relay that has the same pin and amperage configuration. Connect the negative side of the battery cable with a socket. Ignite the engine then have someone turn the A/C controls to the maximum. Observe the clutch. If it engages, then the relay or the fuse was faulty.

Know The Type Of Refrigerant Your Car Uses

Find out if your car uses R134 or R12 refrigerant. This is extremely important especially for newer car models made after 1994. If your car uses R12, hook up the low side hose of the A/C gauge to the low side nipple of the compressor. The low side must have a 7/16 inch screw fitting. Connect the high side compressor nipple with the high side hose of the gauge. This should be a 3/8 inch screw fitting. The process changes slightly if you use R134a refrigerant. Simply push the high side gauge hose on the quick release 16mm nipple on the A/C’s compressor. Then push the low side gauge hose on the quick release 13mm nipple on the A/C’s compressor. A mismatch of these two variants and the A/C system won’t function. Worse still, you will end up with a bad clutch.