WingedMan

94 Accord LX AC blows cool not cold air not cooling car interior in summer

My major concern is to avoid AC compressor locking up due to lack of
refrigerant oil. Locking up compresser lead to break belt that goes around
water pump and alternator as well.

94 Honda Accord LX 5 speed manual transmission 2.2 L engine

while the car is 20 years old it has less than 50K miles on it. Car driven only 1X or 2X per month, but turn on AC for a 10 minutes everytime driven to lubricate the AC system.

The AC does not blow cold air only cool, not enough to cool cars interior in summer heat.

94 Honda original equipment AC with R134A type refrigerant.

Over the past 2-3 years the AC blowing less and less cold air when being used. only cool air

Since I do not use the car much not too concerned about not cooling cars interior my main concern is that the AC compressor does not lock up and break fan belt that also operates the alternater and water pump due to lack of refrigerant oil.

I have been trying to diagnose the problem and fix it myself due to my limited budget and infrequent use of this car.

I opened the hood and visually inspected, so believe the valve to the heater core is being shutoff by the cable from the temperature control valve.

I also believe there is a good level of R134 refrigerant as no oil leaks seen and the AC compressor kicks on (RPM slows and hear change in engine noise) and stays on constantly in summer heat as it is supposed to do when turn on the AC. I understand gauges found in retail stores one attaches to AC system are not accurate and introduce air, moisture, and other problems to AC system, so trying to avoid using them or adding refrigerant.

Also both the radiator fans turn on immediately when turn on the AC and off when turn AC off.

Read something about a bad AC thermostat (seperate from the antifreeze thermostat) seems to be an electrical component and that could be the problem. I am not familar with an AC thermostat, so wondering if my Honda has one, and if that is the problem. How to know if that is the problem, and how to test that electrical component to see if it have gone bad or not. Also what the AC thermostat in that car does, and how it works.

Any advice with someone knowledgeable about diagnosing AC problems in Honda Accord from the 1994 (after R12 stopped being used) to 2010 era
are welcome.

jollyhonda

The low pressure cycling switch will protect the compressor. The oil is suspended in the refrigerant, so if there is enough refrigerant in the system to keep the compressor engaged then in theory there should be enough oil to keep everything lubed. It does sound like you are getting low on refrigerant. In a small system it doesn't take much loss to cause poor system performance.

B20VtecVillain

^^^ Very true, a small loss of a couple Lbs of refrigerant could easily be the culprit for the issue you are having. If you don't have any personal friends that have access to a shop with AC equipment, an off the shelf kit would be your best bet. They are available with oil mixed in or without, and can be easily used without causing any harm to the system. Also the price is right, at about $20-25 or even less.

jollyhonda

The system probably only holds a couple pounds. In systems that size ounces make a difference.

masospaghetti

If the system hasn't been "messed with" (as in, it's still all original), you probably still have enough oil in there and you would be best off adding pure R-134a without extra oil. The extra oil will displace refrigerant and has no ability to transfer heat, so you will reduce the system performance for no reason.

Now, if its been messed with, it may be safer to add a mix of refrigerant and oil since you don't really know how much is in there. But yes, a few ounces of R-134a can make a big difference in system performance.

Are both of your fans working?

B20VtecVillain

Yes you guys are absolutely right, the system doesn't even quite take 2 full lbs. I just looked in my service program and 94 Accord (All engines) only takes 23 oz of R134a and 5.5oz of PAG 46 oil. Very small systems indeed.

tim73

Water pump is driven by the timing belt. But, i have seen the AC compressor/belt lock up an engine so tight, the starter couldnt even turn it over. Of course this was a chevy 2.2 with a serpantine belt. Anyway, your system is prolly just a little low, I bet if you added some( maybe half a can )...youde notice a marked improvement. best to use a full manifold gauge set. But youde prolly be ok to use one of the clip on low side add freon cans.

WingedMan

Thanks for all the input I hope it keeps coming

We owned the car since new, and I believe the AC never been
serviced previously. Mainly, just fluid, filters, and spark plug changes been done to this 94 Accord with less than 50K miles

Yes, the owners manual states only 23 onces of R134A,

and Yes both radiator fans turn on immediately. I tested the
AC in driveway on a warm summer evening. Started the Accord
and radiator fans both off, when I turn on the AC
on both fans immediately came on, and immediately off when
I turn off the AC

Hesitant to add any refrigerant as I no experience doing that, and
read the gauges buy from auto parts store are inaccurate, cannot
find what is proper pressure for the 94 Accord AC system, and
the R134A cans come in 12 oz minimum and I do not want to
overcharge the system that holds only 24 oz

??????? Any further guidance on how to know what the proper pressure is for
this 94 Accord, how to use gauge properly to measure it, and step by step how to add the right amount of R134A refrigerant. Remember I have
no experience with this and have a tight budget. ???????

Mechanic on the radio says he evacuates the AC system of old remaining
refrigerant, then add the full amount of new refrigerant that the system
holds per the capacity defined in service manual. Thinking though
he does not want to lose business to "shade tree mechanics" like myself

Further guidance on this AC matter is sought and welcome

B20VtecVillain

The process isn't an "all or nothing" deal so you don't have to use all of the contents of a can. As far as what to do, you would locate the low side port of your vehicles AC system, connect the hose from the can, release the flow by depressing the trigger and add refrigerant until the gauge reads in the green area. You will not know a specific pressure, but you can test the results once you have brought the needle into the green by disconnecting the can, starting the vehicle, bringing it up to operating temp and then checking the temp of the air coming thru your vents with the AC on.

B20VtecVillain

Also, you should expect to pay $20-25 for a decent can and hose setup with anywhere from 12-20 or so ounces. I would suggest adding straight refrigerant, as it is likely you are not very low on the oil. However, if you do choose a product that has oil added, I wouldn't fear damage as there is not much oil suspended in those cans. The main difference is usually in price, as straight refrigerant tends to be a few dollars cheaper. If your looking for the best deal also then shop around. Pepboys tends to be expensive unless running the product on special, and Home Depot/AutoZone/Advanced Auto/Western Auto etc should all carry what you need, so just compare prices and take your pick.

masospaghetti

The mechanic is technically correct. The only way to get the exact correct charge is by weight - aka, draining it, vacuuming down, and filling by known quantity.

That being said, you can get very close using system pressure and regardless of its correct or not, this is usually how I do it, also because I am usually retrofitting an old R12 system so the capacity isn't exact anyway. You can try one of those little charge kits with the gauges. You will know if you added too much if the pressure begins to climb significantly above 25-30 psi. Again, you really should try and get a manifold set from the parts store, it doesn't cost anything, and you can do a much better job.

WingedMan

B20VtecVillian are you talking about the AC refrigerant gauges that
I have seen in W#lm#rt stores that work while can is being input and pull a trigger to slowly add some refrigerant by pulling the trigger??????? That gauge I believe has green and red area and somehow supposed to adjust it for different outdoor temp (75, 85, 95 degrees Farenheit). They go from 0-150 psi and 0-800 kPa with green and red areas within those ranges. While they do seem like the right price ($15-$25) and seem rather user friendly (looks like I can add refrigerant slowly using trigger and read gauge after adding part of a can without having to disconnect refrigerant can and switch hoses, that seems appealing to me). Those gauges I saw do not come with an instruction manual, so detailed guidance on how to use it properly here is sought and welcome.

The proper pressure reading for AC system have not found in my
owners manual nor Haynes repair manual I have. Anyone with
a link to a proper 94 Honda Accord manual is welcome.???? If not
that have that another reference manual link for car AC systems
with R134a ??????

My H#ynes repair manual states one must have Honda running
while adding refrigerant, so that is what I plan to do while adding
refrigerant.

Thinking I will go to Honda Dealer to buy a 12 oz can of Honda brand
R134a refrigerant with some oil in it (remember my biggest concern it that
compressor not lock up) provided it is similar than the cost
of similar can of another brand that I find in auto parts store

I have read NOT good idea to add refrigerant with sealant, so I plan
to not do that.

Masospagetti what store do I get a manifold AC gauge set to use for free ???? and does it come with good instructions for a novice like myself???
Can one add refrigerant with a trigger while using these manifold
gauges or do I have to disconnect, add refrigerant with a different hose, then reconnect manifold gauge to measure the refrigerant pressure
in my car's AC system. If that exchange of hoses is easy to do or
not for someone without experience???

Also, what do I if I overcharge the system with too much new refrigerant
how do I reduce the amount of refrigerant if I end up doing this ????
keep in mind I am a novice on this repair

Speaking of novice, I see Hi and Low side of refrigerant adding areas
on top front of my Honda engine. I do not know how the hoses to measure
refrigerant pressure or hose to add refrigerant hook up without opening
the AC system to the air. I do NOT want to lose the refrigerant and it
shoot out all over me and the engine when I attach or disconnect these
hoses, so detailed instruction for a novice like myself is sought

Thank you for your past and future input on this matter.
out

masospaghetti

You need the car running or the compressor won't turn on. You will only be able to add a little bit of refrigerant without the compressor running but it will be enough to trip the low pressure switch.

Honda doesn't make R-134a. Just get the stuff from the parts store. You can even get DuPont brand R-134a if you want, its all the same. Here is the good stuff for much cheaper than you can find locally.


If you want to add some oil for peace of mind, get one of these too and add it first.


Here is a inexpensive manifold set. While not super cheap, you will probably make a lot of friends by having one and they pay for themselves quickly.

I must have been mistaken, I thought I saw Autozone had them as a loaner but not anymore (or I was hallucinating). They are not difficult to use. There's a valve you rotate to add refrigerant instead of a trigger. Here is a decent how-to.

http://www.mastercool.com/media/87772-INST.pdf

If you add too much you'll know because both the low and high side pressures will be too high. If this happens, you can easy vent some refrigerant (although this is illegal and you really should take it to a shop to have it recovered).

Most hoses have a coupler where you slide a sleeve back to unlock, then mate the fittings. Then release the sleeve and it locks on. You might lose a little bit of refrigerant but not much.

Try connecting the low-side hose while the compressor is running. The low pressure in the line will make it relatively easy to connect without losing much refrigerant. Once you are comfortable with that, go ahead and connect the high side line.

You can make it easier to connect the high side line by turning off the compressor, as this will reduce the pressure in the line.

You're welcome. IMO getting the manifold set is well worth it. Paying someone for A/C work is really expensive so the equipment pays for itself in no time. The manifold set will also allow you to connect a vacuum pump to evacuate the system if you ever open it up. I know for sure that Autozone loans out vacuum pumps.

tim73

I purchased a set of gauges from Harbor Freight. I used them a couple of times with no issues. After a few cars I noticed I was really struggling trying to get vacuum to holdl, i thought i had leaks in the ac system. Come to find out, the gauges themselves had started leaking at the orings. I went and picked up a more expensive higher end set. Havent had that problem any more.

tim73

Also, years ago I picked up the automotive AC repair guide from haynes. I have used the dog-snot out of that book. It lives in my AC repair tool bucket. It has a good pressure gauge/ ambient temp chart plus many troubleshooting flowcharts. Its a good guide.