A/C compressor not kicking on, not cold!

We're in the socal desert, so it easily gets up to 115 during the summer. We bought the house about a year ago, it was built in 05, and only lived in for a few months....so the air conditioning hasn't had much more than a year of use. House is single story stucco with 1600 sq. ft. It's a goodman air conditioner, as well as goodman furnace/ evaporator in the attic. I can provide pictures and info on both units if needed.

It just started happening this past month. We keep our thermostat around 80-82 usually. When it turns on the attic fan and condensor fan both turn on. Sometimes you can hear the buzzing of the A/C compressor kick on, sometimes not, it's about 50/50. Obviously it's not blowing cold air when the compressor doesn't kick on, just recirculating inside air. Both fans kick on every time. When just the fan kicks on, it can take almost an hour before the compressor kicks on, sometimes less, it's just random. What would cause the compressor to only come on half the time? I've heard it could either be a compressor problem, or capacitor problem, is that correct?

I've done all the obvious maintanence, like replacing filter monthly, checked all circuits, fuses, just cleaned the condensor coils and straightened all the fins a week ago. No leaks, the bigger pipe does get cold, but not icy/frosty cold like I remembered it being last season. Evaporator in the attic...I can't figure out how to get to that thing, looks really complicated. Anything else I should check that I'm missing?

Let me know the steps I should check to get it fixed, it sucks only having air conditioning half the time! Thanks so much for the help!

I think you have likely already checked the obvious stuff, might be time to call in a goodman service tech. You can check this podcast out to see if you missed anything obvious.
Episode #69 - Air-conditioning Troubleshooting checklist

Thanks for the link. I'm just trying to narrow down what to look at and check. Would the problem most likely be the compressor motor itself, the capacitor, low freon, or could it be the thermostat?

A link or knowledge to common symptoms of each one going out would be awesome, I can't really find it. What would cause the compressor and cold air to work only half the time? Thanks allot!

I'm no expert, thats why I interviewed an expert for the show in the above link. That said. I think common sense would rule out low freon if it does cool sometimes. It might also rule out the motor. So, my non-expert gut would tell me it could be a capacitor, the thermostat, a control board or a loose electrical connection.

Okay well here's some pictures of my system. There were no loose wires or bad connections from visual inspection. The capacitor still looks brand new. I'm at a loss here....the only other thing that could be wrong would be low fluid level or a bad compressor correct?

First picture is the data about my outside A/C unit. Second is the label on the compressor. Third is the label on the fan. And the last one shows all the wiring connections and my capacitor, it all still looks brand new. Anything look wrong or connected wrong to you guys? What else can I check? Thanks in advance!

How do the contacts look on the contactor?
Look for signs of burn, pitting or just plain gone.
Basically, you have 220VAC coming in and the T-stat wires activate the 24 VAC coil and pull the contacts in. If the contactor is worn out, then no power will be leaving the contactor to control the compressor and fan motor. Depending on how the contacts land, it could cause intermittent problems.

Is the contactor the big black box in the last picture with all the terminals, that has like 6 or 7 wires connected to it? I tightened all the wires, there was only 1 or 2 that were a little loose. I didn't see any signs of burning, and I don't know what pitting means?

I know that the thermostat wires are the 2 on the far right, where the gray incoming wire connects to the 2 purple wires. Should I just go through each connection and undo it and reconnect them? Would I be better of soldering the incoming thermostat wires to the 2 purple wires on the right?

It's just weird how it works about half the time. The other 50% of the time, the fans will kick on right away, and you have to wait almost 30 minutes before the actual compressor kicks on. Thank you so much for the help!

yep, the black box is the contactor. also check for good connections under and blue wire nuts. soldering shouldn't be necessary. pitting - the contacts on the contactor should be smooth, pitting will make it look round and possibly corroded. These contacts over time will burn/rot away and the contactor will not transfer power when the coil is engaged.
If you have a volt meter, let me know and we can check a few preliminary things that may exclude others. We will first start by checking to see if you have 24VAC to the contactor coil. The results of this check will determine what we need to check next. If you'd like to just change the contactor, the are only a couple of bucks but, make sure you get one of the same amp ratings and pay attention to where the wires come off so you dont' get them mixed up. Do you have any wet spot on the condensor coils that won't dry regardless of anything? This would be the oil residue from a freon leak. They typically will occur at the ends of the tubes (kinda like a radiator on a car).
If the condensor fan comes on w/out the compressor, it's may be a bad compressor.

Cool, thanks for the help. I'll go recheck all the connections hopefully tomorrow, and probably just redo them all. Yeah, I have a voltmeter, please just let me know what connections to check and where they are.

There's no wet spots or signs of a leak anywhere. But it said it was last filled in 05, so maybe after 4 years (even though it's only been used for 1) you need to get the coolant topped off again? Yeah, the condensor fan comes on every time, just the compressor doesn't kick on all the time. It seems to kick on all the time when it's cooler out, or at night. Just during the hottest part of the day that it doesn't want to kick on. Thanks.

If the fan comes on everytime but not the compressor, then we should check the wires that leave the contactor and lead to the compressor and we won't have to work backwards from there. There should be a cover box on the compressor where the wires enter the compressor. Remove the cover and check the connections for corrosion and/or burns. Repair as necessary.
Also, does the casing on the compressor feel hot when this condition occurs?

Yeah, I remember seeing a covered box that was attached to the compressor. I couldn't figure out how to crack it open, but I"ll have to try again.

Were you asking if the compressor casing feels hot while the unit is running? I don't know how to check that, cause the fan would be spinning and I couldn't get my hand in there I don't think. Thanks so much for the help!

yea, we don't want to loose a hand over this.
see if the compressor casing is hot after letting it run (or at least for a few minutes when you think it should have been running). Be sure to cut power to the unit before sticking your hand on the compressor. Be careful it could be very hot. IF you have a infra-red thermostat, that would be the best way to check it otherwise, you'll have to take the grill off the top to check it. when you do this, the fan will come off w/the grill and make sure you have enough slack in the wires to lift it up enough to get a thermostat (non-infra-red) or your hand in there. Does there seem to be a pattern to when the compressor comes on and when it doesn't?

Okay cool, I'll be checking it tomorrow then. I'll check the compressor wires while I'm in there too. I haven't really seen much of a pattern to it, except that it seems to kick on everytime in the evening or morning when it's cooler out. It seems almost impossible to get the compressor to run during the peak hot hours of the day....maybe that's a sign of low coolant?

Well, here's an update for those that care. Found out that I actually had a home warranty that came with our house purchase for free. And they cover A/c repair (minus a $55 service fee). So I just called them up, and they were out the next morning. He checked things out for about ten minutes, then instantly knew it was a 'kickstart' or 'hardstart' kit onto the compressor. And it's been working just fine for the past day. He said if this doesn't fix it, then the only other problem would be a compressor replacement.

I looked up these kits, and it looks like it's an additional capacitor that's connected to the existing capacitor to give the compressor some extra amperage when starting. It was having problems firing up, but now it shouldn't.

Companies actually say that these kits will extend the life of your compressor, won't make the lights dim in the house when it cranks on, and will actually save power. Does this sound like a load of bull, or do you guys actually use them? Just trying to see what everyone thinks of the kickstart kits and if they'll work just fine. Don't want any more problems!

No input on these kickstart devices? Are they any good, or can they cause harm to the system in the long run? I checked it out and the brand is Kickstart, model KZ-RE-357. Anybody else use these?

Hello,

I came across this thread in a google search and I am wondering if anyone might have some advice on the problem I'm having with my AC. The entire HVAC system was replaced 2 years ago and in that time has worked well. In an attempt to be conscientious about maintenance, we contacted a company to come out and inspect the unit, do any cleaning, etc. as part of a regular check up (in other words, there was no existing problem with the unit). A tech came out and looked everything over and said the system was in great shape, but because the readings seemed a little low he pushed some add'l freon in. The unit was not run again until the next afternoon and after being on for roughly an hour and a half I noticed that the house temp seemed to be going up! At first it did seem to be cooling the air. When I went outside I heard the outside AC unit kicking on for 2 or 3 seconds and then abruptly shutting off. It would do this approx. every 10 seconds. I ran back in the house and shut the AC off. We called the same tech and he came back out and (long story somewhat short) he drained some of the freon, which eventually let the outside unit come on and stay on. Apparently there was too much freon in the system, causing the high-pressure sensor to kick the unit off. So now the outside unit will stay on however, the system is barely cooling the inside air - a reading at the vent was 72 degrees where just the day before it was pushing out 62 degree air! The tech took some electrical readings and suggested that it appeared the compressor was failing. He insisted that "nothing he did the day before caused the current problems".

Can you please offer an opinion on this? I am FAR from knowledgeable about HVAC systems but it seems to me that if he pushed in too much freon, which put the system in high-pressure, which caused the compressor to kick on and off every 10 seconds for 1.5 hours that that could cause damage to the compressor - or the system as a whole. Another tech is going to have to come out to diagnose the problem (first tech was not able to) and I know that they will expect payment for diagnostic and repair, however I am concerned because IMO if they caused the damage, why do I have to pay to repair it?

Opinions and advice are appreciated.