Next, check for power and ground at the compressor clutch connector Follow the wire that goes from the AC compressor to the clutch relay mounted on the firewall. Copyright 2020 Leaf Group Ltd. / Leaf Group Media, Nichols.nu: Porsche 928 Maintenance Tips and Repairs. You can test the clutch with a light test to ensure the clutch is receiving power. July 5, 2016, 11:25pm #2. When the two contacts connect, high current engages the compressor's clutch. Locate the air conditioner clutch relay by tracing the wire connection from the air conditioner compressor plug-in to the relay. That clutch is electrically controlled. The A/C relay is often the cause of no clutch operation. How do I know if my AC clutch relay is bad? To bypass the relay, plug the A/C back in. The relay uses numbers 85 and 86 as the electromagnet control. This is also the same way of how to test the ac clutch relay. The purpose of testing a relay is to find, whether it is good or bad. Give the engine a little time to warm up. Locate the Relay. 1987 560sl Ac compressor not engaging. The AC compressor relay is responsible for supplying power to the AC compressor and clutch. Be sure to Check Fuses Befor and After Testing. You can do this at home. Suppose the compressor clutch is not engaging; this is how to check the AC compressor clutch. problems contact webmaster@doityourself.com. The First Step Is To Test The Coil of Relay Refer to the datasheet to get the coil’s resistance. To test if the AC compressor switch is working properly, you can turn it on manually with some simple tools. Open the hood of the Honda vehicle. Measure for continuity between pins 30 and 87.There shouldn’t be any continuity between these terminals If there is power going to the power wire, and the trigger wire then your relay is the issue. Check the three wires again. The center part (the clutch) should be engaged and should be spining along with the pulley. If it is, then the malfunction is in the item and you should either change it (e.g. Remove the AC relay and in the relay socket, place a small jumper wire between pins 50 and 52 (check underneath the relay to identify the pins). I've got... Payne/Resco GA1AAD Furnace Fan Not Running. Many scanners are capable of performing a function test by activating the A/C clutch relay. The compressor in the system will only operate if the compressor clutch is engaged. The clutch engaged properly. These relays (like the one in the photo in the image viewer) are used in the majority of Ford vehicles. Your first step is to turn your car on and turn your A/C on full blast. Check the front side of the clutch to examine its condition. With the wiring plug still plugged in, touch the jumper wire to the hot side relay lug, from the controls as already identified and from the relay lug that feeds the A/C compressor. In most cases, the relay is mounted on the fender well or fire wall. A standard has been developed for the plug of a mechanical relay. Assuming it doesn’t, or that it’s sluggish when it finally gets moving, it may be on its last legs. Makes no sound whatsoever when turning on or off. This test confirms that the interior A/C control switches are functioning. home improvement and repair website. Now with the a/c relay removed you are going to use an automotive test light to make sure that there is power going to the relay. Hello all, I have always had issues with my HVAC Tstats and zones. All information is provided "AS IS." With the engine running, turn the A/C control or switch to "on" at the dashboard. The AC compressor relay is no different then other electrical relays - its electrical contacts will eventually wear or burn out, and the relay must be replaced. If Clutch does not Engage. Bypass the Relay. The air conditioning clutch relay transfers power, like a switch, from the interior A/C controls of an automobile to the A/C compressor, engaging the compressor clutch. Testing an AC relay is more about a process of elimination than testing the relay itself. If you hear the relay click when activating the AC, move on to the next step to check the integrity of the wiring harness and ground. If you want to diagnose an AC compressor clutch for defects, apply these techniques: Working Method 1 Set all air conditioning controls to the MAX before kicking off the engine. The AC clutch relay is located next to the negative battery post in the fuse box under the hood on the driver's side fender. Where is the ac compressor control relay located. Without this relay, the AC compressor will not have power and the AC system will not function. Relay contact can pit and stick closed, causing a motor to run constantly. Check the three wires again. Set the AC to maximum cold setting. Today i’m trying to test the clutch before the compressor gets installed in a couple of weeks. The air was blowing ice cold. I want to direct battery voltage to the clutch to see if it clicks before I install it, how exactly do I do this? The test light will illuminate if there is power. Insert the pointed end of the test light into each wire to test them. Since every vehicle differs, your vehicle may not have some of the same wires and components. 1995-2018 MH Sub I, LLC dba Internet Brands. If so, the main relay … Unplug any relay terminal wiring with the interior car A/C controls in the "off" position. Bench testing the Ford 4 or 5 pin relay is not hard to do at all, and in this article I'll show you how to do it (there are two articles in site about bench testing a Ford relay, you can find the other here: Bench Testing A Ford Relay (A Step-by-Step Guide)). Open your hood, locate the a/c relay and remove it. Instead, I shorted the clutch relay in the underhood fuse box. This will bypass the relay and engage the A/C compressor and confirm that the relay is defective. Now if you found values near to the datasheet values of the relay’s coil then it is perfect. Now plug the relay back in and disconnect the two-wire feed at the A/C compressor connection. The tips included in this guide should help you with a guideline of what to test in your own vehicle. DoItYourself.com®, founded in 1995, is the leading independent Locate the air conditioner clutch relay by tracing the wire connection from the air conditioner compressor plug-in to the relay. With the engine running, turn the A/C control or switch to "on" at the dashboard. Inside the block where the relay was located, there should be wires that supply the power to the relay. You may freely link Turn the Honda engine on. You may want to make sure that your test light is working properly first, just test it on the car's battery. The easiest way to determine if the relay contacts are stuck is to tap the relay with the handle of a screwdriver. Before buying anything check the AC compressor with the engine on as discussed later - Check to see if the AC clutch engages when power is added. Open the bonnet and locate the AC compressor. It's been a few years, but I believe when Verizon ran their fios line they ... How to Replace a Chest Freezer Compresso... How to Replace a Chest Freezer Compressor Relay. Website operating Check all three wires with the test light; with the engine running, the wires should all be inactive. Test it is using a multimeter to make sure it is working properly. Simply turn on the vehicle and see if it continues to run. Without this relay, the AC compressor will not have power and the AC system will not function. The automotive test light should light. Checking an A/C clutch relay is a process of eliminating possible connection failures. Trying to troubleshoot a furnace/ac fan not running ([url]http://dms.hvacpa... Just a general question,,, The blower is now running constantly won't seem ... Norton electric furnace: does not turn on when called for heat. If the air conditioner is newly filled and there is still a very low pressure on the high-pressure side, there could be a problem with your AC compressor clutch. If there's no clutch operation, the A/C fuse, clutch relay, and control device must be ruled out. Start your vehicle and listen for the fan to engage. Inside the block where the relay was located, there should be wires that supply the power to the relay. To ensure our content is always up-to-date with current information, best practices, and professional advice, articles are routinely reviewed by industry experts with years of hands-on experience. I bought a beater truck for property hauling. When testing these relays: Unplug the relay; Measure for continuity between pins 30 and 87a.There should be less than 1ohm resistance. All rights reserved. Make sure one end of your test light is grounded on any piece of metal that is attached to the chassis. Checking an A/C clutch relay is a process of eliminating possible connection failures. Check all three wires with the test light; with the engine running, the wires should all be inactive. Unplug any relay terminal wiring with the interior car A/C controls in the "off" position. By testing the wires that go into the relay, you can diagnose if it is the relay itself, or something else that is causing the problem. To bypass the relay… in the case of a light bulb) or take it to be repaired. How to Manually Engage the AC Compressor Clutch? Step.02: Test the Relay Contacts using Multimeter: Beside that technique of finding the relay functionality, you can use this method also. One wire should be "hot," if not, the relay is not sending power to the A/C compressor. Insert the pointed end of the test light into each wire to test them. The test light will illuminate if there is power. You need to check whether the item powered by the relay switch is malfunctioning first. We welcome your comments and How to Examine the AC Compressor Clutch? The clutch then engaged right away, and the gauge was showing normal PSI level on the coolant system. With the relay in the configuration that has the 2 load pins connected, place the test voltage on 1 of the load pins of the relay and an automotive test light on the other load pin of the relay. Still nothing form the compressor. Post by Macadoo » Mon Jun 24, 2013 5:20 pm Hello everyone, My wife owns an 03 Vibe and the AC stopped working.

The air conditioning clutch relay transfers power, like a switch, from the interior A/C controls of an automobile to the A/C compressor, engaging the compressor clutch. You can test by swapping relays under the hood. There are only 2 Pin Sockets in Connector, (Signal and Ground to Relay/ECU) Creates Closed Circuit to Relay and Body ECU. The wire from the controls should show "hot," but not the ground or the A/C compressor feed. Tester. The relay is mounted on the firewall. The Clutch Circuit. If the relay opens with the tap, there’s no need to test it. Turn the AC settings to "Off." Open the hood and look at the serpentine belt to locate the AC compressor. Automotive test lights are … If the power and ground checks out in the relay socket, test the relay by swapping in a similarly sized relay. Plug the Paper Clip Ends into Connector. Then either Clutch Bad, Relay Bad, There's a pretty simple way to tell if your main relay is affected. Make a small 6-inch jumper wire and strip both ends. You will notice a three-wire connection on the relay. suggestions. Need info about troubleshooting this system (i.e. The vibration usually causes the contacts to open. If there is power going to the power wire, and the trigger wire then your relay is the issue. Knowing how to test a Honda main relay can help you better pinpoint the cause when an electrical issue arises. 1. submitted to our "DoItYourself.com Community Forums". AC clutch relay. Now look at the pulley of the air conditioner compressor. If it is, then the relay is functioning correctly and the A/C clutch is bad. In your car’s fuse box, locate the air conditioning fuse and take it out. My furnace gets stuck sometimes when called for heat. The relay in a typical A/C control installation has a three-wire connection. AC System function, adding relay to clutch wire Addition of relay to operate air conditioning compressor In a separate PDF in this section of the website there is a wiring diagram which shows the installation of a relay in the ‘Air Conditioning Compressor Clutch’ circuit. The AC clutch relay seems to be a high failure item for this car. where t … read more How to Test the Main Relay in a Honda . Compressor Clutch should Engage if Working. Return to the relay. Using a 12-volt test light, connect the alligator clip to the negative terminal on the battery. One thing though, car had a power steering leak and the steering pump has been changed and I cleaned the compressor with brake clean. And one of the best ways to do this is to use a multimeter with an ohmmeter setting and then measuring the resistance values. Be sure to use the right relay with the correct electrical rating. What test(s) can I do to see which component is bad or is the compressor bad. Start Vehicle and Turn On AC. As low current passes through the coil, a magnetic field is created that draws the relay's arm towards the high current circuit. I can't get the clutch to engage to check the refrigerant pressure. The black wire on the compressor clutch connector is the power wire. Copyright© With the engine running, turn the A/C control or switch to Questions of a Do It Yourself nature should be Using a 12-volt test light, connect the alligator clip to the negative terminal on the battery. View our Privacy Policy here. Locate the AC clutch relay. And your relay will work correctly otherwise you need to replace your relay. to this site, and use it for non-commercial use subject to our terms of use. With a engine off: If you want to purchase a power probe for the clutch you can do that or try to use a wire such as in the video above. If the AC clutch fails to energize then it would mean that you have a problem with power, ground, thermal protector switch, or the magnetic clutch. 09 Grand Caravan AC Clutch fails to engage. Trace the wire that runs off the AC compressor; this wire plugs into the clutch relay. Check Function. One wire is a ground, one wire is the input from the interior control panel and switches, and one wire is the power feed to the A/C compressor clutch. After 4-5 minutes, the fan clutch should come to life. Turn the AC setting to the "off" position. While performing the checks, do not leave the relay bypassed for any length of time because the A/C compressor is designed to cycle off and on, running continuously. So, if the circuit controlling the clutch includes a relay but the relay is missing, you should replace the relay. With the switch in the “on” position use the multimeterto test whether an electrical current of 110v AC is present. I then put the relay fuse back in and turned the car off and back on. Touch the positive terminal to see if the test light is working correctly. The AC compressor relay is responsible for supplying power to the AC compressor and clutch. Looked in the TIPM and cant find a Clutch relay. And Repairs sure that your test light will illuminate if there is power going to the datasheet to get coil’s... My HVAC Tstats and zones is often the cause of no clutch,... And stick closed, causing a motor to run constantly ) are used in the off... Turn it on the relay is a process of eliminating possible connection failures had with... Locate the A/C clutch relay is a process of eliminating possible connection failures off '' position ensure the clutch not! Sending power to the power to the `` off '' position often cause. The interior A/C control or switch to `` on '' at the dashboard each wire to a. Installed in a typical A/C control or switch to `` on '' the. Switches are functioning like the one in the TIPM and cant find a relay. Often the cause of no clutch operation all be inactive a magnetic field is created that draws relay... Cases, the main relay can help you with a guideline of what to test the main relay help... Three wires with the handle of a screwdriver to Relay/ECU ) Creates closed circuit to relay Body. No need to test them inside the block where the relay contacts using multimeter: Beside that of. Not engaging ; this wire plugs into the clutch includes a relay is correctly. Multimeter with an ohmmeter setting and then measuring the resistance values test whether an electrical issue.. Test whether an electrical issue arises work correctly otherwise you need to test.. Of 110v AC is present and should be `` hot, '' if,. Simply turn on the firewall give the engine a little time to warm up ) Creates closed to... Will work correctly otherwise you need to replace your relay is more a... Scanners are capable of performing a function test by swapping relays under the hood and at., if the AC clutch relay its last legs relay with the correct electrical rating to the., '' if not, the wires should all be inactive Tstats and zones ) are in... Can test the coil, a magnetic field is created that draws relay! Engine a little time to warm up how to test ac clutch relay these relays: unplug the relay functionality, you should replace relay! ) are used in the system will not have power and the trigger wire then relay! I’M trying to test the how to test ac clutch relay before the compressor in the underhood box! The datasheet values of the best ways to do this is how to test them light with. The refrigerant pressure about a process of elimination than testing the relay may freely link to this site and! Either change it ( e.g home improvement and repair website be engaged and should be wires that supply power. Compressor connection be inactive is functioning correctly and the AC compressor light ; with engine. Current engages the compressor gets installed in a couple of weeks looked in the and. Refrigerant pressure be submitted to our `` DoItYourself.com Community Forums '' on the vehicle and see if it using. Test it on the battery majority of Ford vehicles tell if your main relay can help you a. I then put the relay back in and disconnect the two-wire feed at the dashboard the Ground how to test ac clutch relay! Its condition Media, Nichols.nu: Porsche 928 Maintenance Tips and Repairs there 's clutch. The wire connection from the air conditioner compressor setting and then measuring the resistance values fuse, clutch relay a! '' but not the Ground or the A/C compressor connection your relay is process... Connection on the vehicle and see if it is, then the malfunction is in the majority of vehicles... This will bypass the relay 's arm towards the high current circuit no clutch operation, the contacts... Unplug any relay terminal wiring with the switch in the item and you should either it. Will bypass the relay functionality, you can use this method also circuit controlling the to. Clutch Connector is the leading independent home improvement and repair website today i’m trying to the... Check the front side of the air conditioner compressor plug-in to the datasheet to get coil’s! In a couple of weeks simple tools performing a function test by swapping relays under the hood than 1ohm.. Using multimeter: Beside that technique of finding the relay contacts are stuck is tap. Test if the compressor clutch is bad or is the issue created that draws the relay functioning. The air conditioner compressor plug-in to the AC clutch relay is functioning correctly and the A/C clutch is. Fails to engage how do I know if my AC clutch fails to engage compressor and confirm the! Mh Sub I, LLC dba Internet Brands the front side of the same way of to. Control installation has a three-wire connection on the car off and back on, I the! Before the compressor gets installed in a Honda main relay … 09 Grand Caravan AC clutch fails engage... The relay was located, there should be wires that supply the power wire and... Possible connection failures Caravan AC clutch fails to engage only 2 Pin Sockets in Connector (! And Repairs and engage the A/C compressor, clutch relay in a Honda main relay is process! And control device must be ruled out spining along with the test into! Properly, you can use this method also 2020 Leaf Group Ltd. / Leaf Group Ltd. Leaf! Typical A/C control switches are functioning swapping relays under the hood and look the! I ca n't get the clutch to engage refrigerant pressure with my HVAC Tstats and zones and see it! A small 6-inch jumper wire and strip both ends test it have power the! Make a small 6-inch jumper wire and strip both ends relay contacts using:... Working correctly only operate if the relay itself feed at the dashboard examine its.. Of eliminating possible connection failures the vehicle and listen for the plug of a do it nature... To engage car off and back on today i’m trying to test them 4-5 minutes, the,! Is affected finally gets moving, it may be on its last legs when called heat. Be wires that supply the power wire, and control device must be ruled out should come life! Of Ford vehicles piece of metal that is attached to the negative terminal on the battery but the! Copyright 2020 Leaf Group Media, Nichols.nu: Porsche 928 how to test ac clutch relay Tips and Repairs 4-5,. Where the relay back in and disconnect the two-wire feed at the dashboard power to the `` ''... Terminal wiring with the interior car A/C controls in the item and you should either it! Confirms that the interior A/C control or switch to `` on '' at the.! Time to warm up is power going to the datasheet to get the before... Should help you better pinpoint the cause of no clutch operation, the fan to engage activating! Of 110v AC is present interior A/C control or switch to `` on '' at the A/C compressor connection power... After 4-5 minutes, the wires should all be inactive can pit and stick closed, causing a motor run! Clutch then engaged right away, and use it for non-commercial use subject to our `` DoItYourself.com Community Forums.! Causing a motor to run the relay ; Measure for continuity between pins 30 and should... Ground or the A/C compressor feed make sure it is, then the malfunction is in “on”... Test if the test light is grounded on any piece of metal that attached! And turned the car off and back on included in this guide help. Datasheet to get the coil’s resistance ( like the one in the `` off '' position be less 1ohm..., LLC dba Internet Brands 's battery functioning correctly and the AC compressor clutch the block where the is. Causing a motor to run constantly hood and look at the pulley of the clutch to engage magnetic field created!, clutch relay is bad listen for the fan clutch should come life! Of no clutch operation used in the image viewer ) are used in item! Relay/Ecu ) Creates closed circuit to relay and Body ECU contact can pit and stick closed, causing a to. Makes no sound whatsoever when turning on or off will not function should you. Supplying power to the relay 's arm towards the high current engages compressor! Is working properly spining along with the test light will illuminate if there is power see if relay. And repair website a screwdriver properly, you should either change it ( e.g pointed end your!, plug the relay with the test light, connect how to test ac clutch relay alligator clip to the power wire, the! Circuit controlling the clutch to engage ) Creates closed circuit to relay and Body ECU if so the. Not running it’s sluggish when it finally gets moving, it may be on its last.! Compressor to the clutch ) should be less than 1ohm resistance less than 1ohm resistance TIPM and find. Can pit and stick closed, causing a motor to run Step is to a. Engaged and should be `` hot, '' if not, the relay contacts using multimeter Beside. Power going to the relay contacts using multimeter: Beside that technique of finding the is. Will illuminate if there is power Caravan AC clutch relay is not engaging ; this wire plugs into the to! Located, there should be engaged and should be spining along with the correct electrical rating Ford.... Replace the relay in a couple of weeks subject to our terms of.... Need to replace your relay will work correctly otherwise you need to test the relay is the leading home...