alloysr16s

Hello Honda Tech,

It has been a while since I have been in the forums. I have searched the threads for my air conditioning issues, but it seems that I can not find anything similar.

I had a NEW ac compressor and condenser installed on my 2008 Honda civic because it was blowing warm air. After it was installed it worked well for about a month and it started to blow cool to cold ( frigid ) to warm air. It did not test it with a thermometer to make sure that it was definitely cold and cool air, but I can tell because it blows so cold sometimes that you feel that your have to put a coat on. I noticed that it blew warm arm last night ( about 75 deg , in NYC ) and then as I was driving about a mile down the road it turned cool. My clutch engages because I see it turning. Today was a high of 84 and I drove it in stop and start traffic and it worked. I hear the compressor turn on when I turn the AC on and off. I took it back to the mechanic and he said that he could not find anything wrong. He did say when it happens again to bring in the car .My wife was pissed because she loves AC and we dropped 1200 dollars fixing the ac NOT even 2 months ago. If anyone can give me some advice or has been in this same situation please let me know. Thanks!

rd2smoker

someone with detailed 8th generation air conditioner experience correct me if I'm wrong, but isn't there some sort of a valve that turns on to let the system flow?

alloysr16s

Thats a first I have heard about a valve. I have heard about a filter or hose being dirty. I called a local chain repair shop and the guy said maybe the electrical socket that gives the compressor power may have some corrosion? Maybe a relay? I am bring it back to my mechanic because he installed the system

rd2smoker

The relay is not marked in the car or in the book, my AC was "fading" when it got hot out side. It took some work with a volt meter to figure out which relay it was. The relay was starting to burn up and like a coil pack on a motorcycle, it would work fine when it was cold but would loos continuity when it got hot and at some point it just never kicked back on. New one was 5 bucks and now no "fading". Its one of the black 1"x1"x1" relays in the under-hood fuse box.

I'll take a pic tomorrow.

ether way....its a easy try and its easy for a shop to say its something else.

rd2smoker

I'd change this before dropping more Bucks on the system.

alloysr16s

I will try this first. I am just a little heated because " my " mechanic had changed the compressor and the condensor like it was the problem. Hopefully this will help. I rode to work today and it was cold all the way to work.SMH. I will change the relay and see what happens. If you can think of anything else let me know. Does you feel that your AC blows cold air all then time now since your changed the relay?

rd2smoker

Yes its 100% now. Its in the 100's right now here in TX so I run it 24/7 haha

alloysr16s

I went to the auto store and asked them about the relay and he said the accumulator/drier could be the issue. He said because since my ac blows cold air that the filter might be dirty and possibly needs to be replaced. He said the has to be replaced because when the compressor goes pieces of metal will go to the accumulator and if not replaced will go back into the system. Hopefully it was replaced or not, so this can get resolved

rd2smoker

I don't know about that whole "metal pieces". Did you try the relay? Its only a $5 part.

alloysr16s

Well first they didnt have it in any of their stores and secondly they said that is only if it blowing hot air. My car will blow cold air for kost of the day and then for ahort period of time it will be lukewarm. I am going to swap relays to see if it will work. I will keep you updated

James89DX

The fact that your AC blows ice cold, even if only occasionally, indicates there is nothing wrong with the charge level/drier (also referred to as an accumulator)/etc.

What is more likely is that you either have an intermittently failing clutch - but this seems unlikely since you said it consistently engages when you press the button on and off. If you are CERTAIN your compressor clutch is not the issue, then -

I would bet the evaporator temp switch is bad and/or failing. Not sure what Honda calls this part, but Nissan calls the part the "thermo control amp". Nissan had widespread troubles with this part from the mid 90's all the way up through the 2000's. The part is the temp switch on the evaporator box, which is what controls the cycling of the system during normal operation (i.e., when the evaporator temperature reaches, say, 37 degrees, it cycles the compressor OFF. Then when the evaporator temperature reaches, say, 40 degrees, it cycles the compressor back ON - this would be your normal cycling scenario for an automotive AC system which allows the vent temp to stay between a steady 40-45 degrees or so).

Anyway, when this part fails, it allows the compressor to cycle OFF for long stretches. This means your system will go from blowing ice cold to blowing lukewarm or even warm air intermittently - because this evaporator temp switch is sending false/incorrect readings.

Nissan calls this notoriously fail-prone part the "thermo control amp". I don't know what Honda calls it but it may just be called "evaporator temp switch" or "thermo switch" or "temp switch" or something like that. Some systems also have an outside ambient air temp switch which prevents the compressor from engaging during extremely cold temperatures. I know my 92 Maxima has such a switch. If the newer Hondas do (I know my 89 Civic does not), then that would also be something to check.

I don't have a newer Civic and have never worked on one, but as I said above, your intermittent troubles are symptomatic of textbook evap temp switch issues that I've dealt with on both of my Maximas. It's very annoying. I replaced one a year ago and it's already acting up again. Maybe this can help steer you in the right direction. I would doubt replacing some random relays is going to fix your problem.

*edit* ALSO - unfortunately almost any shop you ever go to for ANY AC problem, the shop is ALWAYS going to tell you it's the compressor. And this is ALWAYS going to cost you about a grand no matter what. It's pretty much a shop's default diagnosis of any AC problem, unfortunately. It's a huge racket IMO. It's why I've taught myself to do my own AC work and purchased all my own AC tools over these past few years.

James89DX

Here's a diagram I found of the 8th gen evaporator switch. Looks like Honda just calls it the "evaporator temperature sensor". Luckily for you it appears replaceable without discharging the system and pulling out the evaporator (unlike my Maximas, very annoying).

This should be found under/behind your glove box area. That's where it is on most cars.



I'm not certain you can do this on the 8th gen Civic, so you probably want to consult a wiring diagram first - but on my Nissans I'm able to jump that switch when it's acting up and it immediately re-engages the system thus confirming the evap switch is bad.

rd2smoker

^ good info

alloysr16s

Thanks alot for the info. I am going to check out the location and give it a shot

alloysr16s

I appreciate the help Honda tech has given me.

Casey

iTrader: (5)

The relay is a known problem on these cars. As mentioned before, replace it. If its not bad now, it will go out eventually. I replaced mine this past weekend.

alloysr16s

I just wanted to let everyone know that my AC now does NOT work. It went from freezing to cold to luke warm and everything in between. Now it does not blow anything but hot air. I have not had a chance to take it back to the mechanic. Its going there asap

Jujutsuka

Your A/C is blowing hot air even though the clutch is engaging?
I take it you have recharged.
I am more familiar with RSX but I assume Honda Civic might have the same thing. A diagnostic that can be ran on the cars A/C by pushing the A/C buttons a certain kind of way. If the Civic is able to do that then I think you might be able to figure out whats going on. Sounds like its going to be a sensor/module issue.

James89DX

Like the guy above asked, are you certain your clutch engaging or not during these outages?

I would assume the clutch is NOT engaging, because if it were engaging there is no reason it shouldn't cool assuming it has a proper charge level.

If the clutch is NOT engaging you need to figure out if it's not getting 12V sent to the clutch. If it is NOT getting 12V sent to the clutch then you have an electrical issue somewhere (i.e., this relay everybody keeps mentioning or the evaporator temp switch). If it IS getting 12V sent to the clutch and the clutch is not engaging then you have found the culprit - the clutch itself.

Now the problem with this being intermittent is that it's difficult to definitely test 12V to the clutch by yourself when you're driving it or if you can't repeat it in your driveway. Here's what I did to test it:

I got a 12V powered LED and some length of wire. I tapped the 12V side of the LED into the compressor power wire (you can just use a side tap here). The other LED wire will just go to ground obviously. I just set the LED in my passenger floorboard. This way, when my AC would intermittently go out while I was driving I could look at that LED and instantly tell whether or not the compressor clutch was being sent 12V (LED lit up = compressor being sent power, LED not lit up = compressor not being sent power). Since I initially suspected the clutch was bad, I was expecting to encounter a situation in which the AC was NOT working AND the LED was lit up (meaning clutch was receiving power but was just not working). Instead I found the LED was not lighting up during these outages which meant the problem was not the clutch. And that is how I ruled out the clutch and then narrowed it down to my evap temp switch.

You don't have to have an LED, you can just use any 12V powered normal bulb or whatever.

alloysr16s

Thanks everyone for all the help. I have not checked to see if the clutch is engaging as of yet. When this stuff happens I am always driving with a purpose so I have not have the time to check to see if the clutch is engaging. I will keep everyone updated after I go to the mechanic

alloysr16s

So I finally was able to see that the clutch was not engaging when the AC was turned on. I just wanted to give people a heads up

Jujutsuka

Now just have to figure out why it's not engaging.
ElectroMagnet bad?
Pressure low?
Pressure switch bad?

Does the condenser fan turn on?
Is there voltage at the relay?
Also test the continuity

alloysr16s

[QUOTE=Jujutsuka;50509700]Now just have to figure out why it's not engaging.
ElectroMagnet bad?
Pressure low?
Pressure switch bad?

Does the condenser fan turn on?
Is there voltage at the relay?
Also test the continuity[/QUOTE

I did not do any tests. I have very limited experience and I will let you know once I bring it back from the mechanic, who replaced the condensor and compressor

Jujutsuka

[QUOTE=alloysr16s;50510511]Hopefully hes backing up his work since he didn't solve the problem last time. I actually just had to fix my own A/C three weekends ago. My electromagnetic coil ended up having an open circuit. So I disassembled my compressor on my RSX and and replaced the coil, pulley bearing, and a/c clutch plate. Good luck to you.

rd2smoker

Ahh the "new stuff is broke" issue. ......