A couple of years ago, I purchased a used 2004 Acura TSX, artic blue, 6 speed. I have always liked this body style and with the price of fuel, being what it was/is, thought it would be wise purchase. The car seemed fine, ran good but had two issues: 1.- The Passenger door solonoid would not work. So I promptly ordered a new one and replaced it-works great now. 2.- The A/C unit compressor would not shut off- meaning that the compressor was always running and putting out cold air in the cabin.

This was in November and having the A/C always on was not desireable. So I figured out that the problem was the A/C mode switch on the HVAC/Radio circuit board. It would not turn off. Using a TSX wiring diagram schematic, I traced the wire on the plug to the compressor and installed a manual on/off switch to turn off the compressor when not needed. This worked well for a while then the compressor started acting up and not cooling. I was afraid I may have encountered the "Black Death".

I decided to purchase a complete new quality compressor kit which included the A/C compressor, expansion valve and receiver/drier for $250.00. The kit also contained freon oil and line flush to flush and clean the lines. I also purchased a new condensor $85.00. (goes in front of radiator) In my opinion, if you drive a 2004, 2005 and perhaps 2006 and are still on the original compressor, you are living on "borrowed time" and it is just a matter of time before you have the dreaded "black death". So with the "pay me now or pay me later" mentality, I recommend you change them now and do the job once and correctly!

I installed the A/C kit but I have been working around cars for a while. If not sure of your abilities in this area, be sure to get a qualified A/C person to install. (also it is a very good responsible idea to evacuate the old freon using evacuation equipment and not just release the freon into the atmosphere. The biggest challenge is the Expansion valve installation which means installing by removing the glove compartment and the side cover of the expansion valve box. Be sure to use all new O-rings and use A/C oil on installation of the O-rings.

On installation of the A/C kit, vacuming the system and charging with the exact amount of R-134 freon. The system worked and cooled great!

A few weeks later, the A/C system became intermittent and would work, then cut-off and not work. During the hot Texas summer, this was just not satisfactory. I also came across, a used HVAC/radio console board and replaced that, thinking that the original board was giving additional problems. The A/C started working again but only for a day or two. Then it became intermittent again- bummer.

So I started swapping out the relays, and noticed that it would work then stop working. I knew that not all the relays could be bad at once. So I went to the upper middle relay- the A/C compressor relay, and put my finger on top of it and "wobbled" it while it was in it's socket with engine running and A/C on. I could hear the A/C compressor cut in and out. I then knew I was on to something. I stopped the car engine and removed the A/C relay and took a file to the four prongs and not only removed the glaze, but cleaned and ruffed up the connection areas for good contact. I also took a pair of pliers and gently added a ever so slight curve to the surface of each prong. This was to ensure a good clean tight contact with the socket that the relay plugs in to. I also coated the four prongs with di-electric grease to preserve the contacts.

My 2004 Acura TSX A/C system has never worked better!! It cools extremely good, with the exit air temperature at 40 degrees.

I hope my experience helps some of you, and if it does, reply to the post and send a word of thanx!

Good Luck!

 

I have a 2004 with about 80,000 miles on it. Had the compressor relay replaced once. If my AC becomes intermittent again, I'll definitely do the wriggle test. Maybe the relay was fine, the contacts were not good, and the replacement of the relay just established better contact....Thanks

 

Intermittent electrical problems are the bane of my life too. Since the solid state stuff seems to survive longer than the mechanical parts, your writeup points out the wisdom of checking relays and connections first. Did you ever figure out why the compressor ran continuously - was that caused by the relay?

Thanks for the repair tips,
Glenn in New Braunfels

 

In answer to the following question:
"Did you ever figure out why the compressor ran continuously - was that caused by the relay?"

The compressor ran continuosly because of the HVAC/radio circuit board- seems the actual non-replacable on/off switch on the board went bad. I replaced the circuit board with another one, and the AC compressor turns on/off as it should. By the way, these circuit boards are over $1000. at the dealer, I picked one up on Ebay for around $200. The units are fairly easy to install, just don't forget to remove the two 8mm bolts located on the bottom of the radio portion. Along with the one screw behind the emer. light blinker and the two alone each side, accessible by removing the plastic trim by gently pulling it out.

One other tidbit I want to leave you with is that, in the lower left corner of the radio area on circuit board, you will see a four character code i.e. 7EAO. If you need to replace your HVAC/circuit circuit board, be sure to get one with the exact code that your vehicle has. Otherwise, it may or may not work correctly( most likely it won't) and a common problem of a circuit board mismatch is a radio and clock that will not work correctly.

Cheers!

 

Very fine sleuthing, Bulterier! Your description reads like a detective mystery being solved through intuition, logic, and dogged persistence.

Now that it is 6 months later, is it still working properly?

 

This is a great post. I also have a 2004 TSX - 5AT though. I purchased the car used back in November 2008. Unfortunately I never checked the A/C and to this day the car blows only air-temp air. I've had it checked multiple times, there are no leaks, the compressor might be shot, no one knows. I'm done on my warranty and I'm sick of replacing parts that don't necessarily need to be replaced because the mechanic misdiagnosed the issue.
If only you lived in New Jersey - I'd pay you just for a detailed diagnosis!

 

I purchased a 04 used, one of the receipts I got from the previous owner was for the AC system. It was $2k plus bill, but picked up by the extended warranty he bought (lucky guy).

 

Is there a possibility you can take a picture of where this relay is located I have no idea where it might be.

 

Many Thanx for the kudos!
Yes, my A/C is still working just fine!
This is the first time I have been back to this site, since all is well with my TSX with no issues.
I have spent my time restoring what I enjoy the best, Honda motorcycles from the 60's to the early 70's. Just completed restoring a 1966 Honda Cb450 Black Bomber.

In answer to your question on the actual location of the relay, sure in the next couple of days, I will indeed take a pic and post it on here.

Takes care!

 

Here in the middle of this Hot Texas Summer, I started experiencing intermittent Air Conditioning issues. If the outside temperature was over 90 degrees, my 04 TSX A/C compressor would disengage and start blowing warm air. At night or when I would first start the vehicle with the engine cold, the A/C would blow nice cold air.
So I did some research and purchased the new style compressor relay Honda part no 39794-SDA-A05 and replaced the older style. Did not help, I still had the same problem when the ambient temperature reached over 90 degrees F. I hooked up the compressor Freon gauges and my readings were for low- 35lbs and high at 225 lbs. - fairly normal readings.
So I decided to go to back to basics and see if I needed any water/coolant in the radiator. To my surprise, I had to add about a quart to half gallon of water. I then drove the car again and my intermittent A/C was solved. This I find strange since my engine temperature gauge always read less then half way on the temp. gauge.
I am thinking that there is a sensor that if the engine gets too hot that it will shut down the A/C until the engine cools back down again.

So another thing to check if you have intermittent A/C problems is the engine coolant level. Just might solve your problem and keep your engine cooler as well. With an aluminum block and head, overheating can lead to severe engine problems.