AC Won't Start - How To Troubleshoot & Replace a Contactor - 1 Pole vs 2 Pole

Here I explain how a contactor works in an air conditioning system as well as how to replace a faulty unit. If you need a new contactor be sure to do the following:

1 - Be sure to confirm the coil voltage.
2 ‐ Order the correct number of poles.
3 ‐ Verify that the replacement is at least the same or higher amperage as the one you are replacing.

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Blessings,

Ben

[BenjaminSahlstrom]

You guys are awesome. As an affiliate I earn from qualifying purchases.

[warveteran-]

I know this is old, but it saved me thousands. My ac unit kept blowing the 3 amp fuse on the board, I had checked every wire, thermostat, grounds, and couldn’t figure out what was going on. I watched a video that showed to check the ohms from the sides of the contactor. I checked and mine was only at 1.9 ohms. The video I watched said it should be over 17 up to 20 something. I ordered the $15 part reluctant that it was going to work. Well I switched it and the ac works great!!! These videos are money savers. Thank you for posting this video!!! Hope this helps someone

[gregrobsn]

Good video. My only issue as a 45 year industrial maintenance electrician would be never depress the live contactor with the cover off and no safety glasses. I've seen too many of these arc if you have a short down stream or a frozen compressor rotor. The arc flash can blind you or throw copper plasma into your face. Just a thought. Most of the voltages I worked with were 480 vac or 4160 vac. But that doesn't mean 240 can't get you.

[GenoFelice]

Had 2 free estimates to fix my AC that wouldn't turn on. 1st wanted $1500. Told me compressor needed to be replaced. 2nd told me contactor was bad and wanted #165 to replace. Watched your video, replace both my contactor, which was working buy old and dirty, and my capacitor. Cost me less that $30 on Amazon. Glad I watched this video !!

[bluesteel]

Best presentation of a repair I've ever seen. Clear and concise.

[StylingBuddy]

Simply one of the best repair presentations I have seen on Youtube. Well done!!

[VV-this]

Thank you so much. I am a sixty-year-old woman and your directions are perfect, easy to understand.

[condor]

Great video Ben! I just yesterday removed and replaced my single pole Packard contactor with a new one. The old one was 4 years old or something and cost like $20. Cheap maintenance and only takes like 15 minutes. As an aside, I took the old one completely apart. It was a Packard just like the one you had. It was really easy to remove all the individual components and see how badly the contacts were pitted. They were pitted to a certain extent and had black carbon on them from all the arching. I used a drywall sanding block and wire brush to clean up the contact surfaces.. I then reassembled and put it in storage for future use in case of an emergency. Cleaning it up made it almost new again I would say but it will definitely due good enough on a weekend if needed. The bottom contacts remove easily with just a screw removal. The only tricky part was removing the top contacts that move down when the coil is engaged and where you manually push it in as you demonstrated. The little spring has to encircle a dimple on both mating surfaces in order to stay in place and function. That was a little tricky to remove and to replace the spring back. But you have to remove it since it allows you to turn the one piece contact 90 degrees and remove it out of that its holder for access to the surfaces. Very fun project. One you could educate you son on like I did with my 20 yr old! Thanks again!

[makkusu]

Thank you for your clear and detailed presentation! I've watched a number of home HVAC repair videos and this was far and away the most helpful.

Never worked on HVAC before in my life but got my AC running again for less than $75 (including the multimeter) with your help.

[byteman]

Benjamin! You Rock Sir! Thank you for explaining in detail what my A/C guy wouldn't. You Sir should open a school! You have TALENT!

[choimdachoim]

I was the Handyman for an apartment building in North Hollywood for a couple years and had problems with grains of sand getting between the contact points in the roof-top A/C fan-units. The Building Manager thought I was a super guy because I kept fixing these A/C problems for her, saving tons of money.

[Islandman]

Excellent vid, great info and very detailed! Thanks Ben and you look so young with so much knowledge of your craft!💪🏼 I’m a DIYer, don’t really call a professional unless it’s way over my head or don’t have the necessary equipment. So I find your vids very enlightening! Keep it up! You got my subscription!

[allenbozeman]

Your video was SUPER HELPFUL. I am replacing my single pole contactor (30 amp). In your video you didn’t talk about the LRA numbers on the contactor. My old one shows 150 my new one shows 180. Can I still use the new one?

[TheWilferch]

If your OEM contactor is rated at 25A....would a higher Amp rated replacement be considered a "heavy duty" version? Costs only a few bucks more and in most cases I'm finding that the mounting footprint is no different for a 25A unit vs a 30A or 40A unit.

[Inspironator]

That was a very thorough explanation and process. I would add that at the end, you discovered the spade connector on one side of the 24V coil wasn't tight. This may be the reason the contactor wasn't pulling the contacts closed solidly. So when the contactor vibrates as you showed, the quality of the coil connections should also be suspect. Sometimes, its easy to find fault with a part when it may be something else that could cause the same behavior. Having a new contactor with higher quality should provide trouble-free service for the life of that unit, though.

[alanrodgers]

Awesome video. thank you for all the clarity. The only place that I am still unclear is the two 120 wires feeding the AC contactor are stranded. Should they have a crushed lug metal connector and then inserted in the new AC contactor that has the screws?

[nelsonsantos]

Awesome presentation, thoroughly explained, great job! A question though. Does short cycling the AC causes damage to it. I thought y AC stopped working, so I lowered the thermostat and it ran, and then turned up the thermostat, so now it doesn't run anymore.

[ryanybos]

Awesome job explaining 1 Pole vs 2 Pole Contactors and a great deal more. You have a gift Ben, thank you for the tutorial brother

[mono]

very thorough and informative. My unit was buzzing but the fan was not rotating So I guess I need to see your other viseo. Thank you so much

[erickj.]

Awesome video! Thanks to you I was able to trouble shoot my condenser; found the problem was the contactor, and was able to replace it saving me $730 and AC company was trying to charge me for fixing a "very complicated issue." Thank you for an epic video!!