Need A/C Help - Opposite Issue of Most...

[Racinfan83]

98 Civic EX. A/C not always blowing cold enough. Spent a couple hours messing with it and another couple searching online for this problem to no avail.
The issue is the OPPOSITE of most A/C issues. Most people can't get the A/C clutch to come ON. I can't get mine to shut OFF. It is on constantly at idle - which is dragging the motor down and making it get hot. It will cycle off briefly when you press accelerator but then it comes back on and runs constantly until you drop motor back to idle and then gas it again. Put gauges on it - low pressure at idle hangs around 40 and high at around 210. 97 degrees outside. When you rev it up to about 3k rpms the low pressure will go up to about 80 and high to around 300 but clutch stays on. Condenser fan and radiator fan work fine. Blows cold air most of the time but not always - which is ok but due to the lack of power this little motor has, the A/C compressor being on all the time just KILLS the car. I have kind of a intermittent flutter at cruise speed like it's missing but no CEL. Just feels like a miss and no power because the A/C clutch is on constantly. It didn't use to be that way - used to feel the car drag down as it cycled?
I changed distributor recently, and reset timing by the book. At least I think so. Put timing light at a slight angle toward back of motor in order to see v notch and marks and set it on middle of the 3 marks?? With the connector inside passenger kick panel jumped and CEL on as it is supposed to be to set it.
SO - any ideas from the A/C experts?

 

[mc360]

Every think about just turning the ac switch off? These motors you can feel a big difference when turning ac on and off, when the account is working correct I believe the clutch is not supposed to constantly cycle off and on.

 

[Racinfan83]

I shouldn't have to manually turn it off and on. The clutch is supposed to cycle, not run constantly. Fast cycling is a sign of low freon, this one has been low and still doesn't cycle right. It has correct charge in it now to my knowledge...

 

[mc360]

If it wasn't cycling with low freon then maybe the compressor is the issue? I have been researching ac issues since I'm having them on all 3 of my vehicles, I always thought it was normal for the compressor to cycle off an on (not fast) but Google told me different. My 4runner ac hasn't worked in 3 years so I started fixing it, had a hole in the line so I changed the line,drier,expansion valve and refilled it to full charge and the compressor runs constant never cycling but still doesn't cool past 60 degrees so I think it needs a new compressor.

 

[Racinfan83]

Yeah I don't know at this point. I know it used to work great and it cycled on and off about 30 seconds each way. It blows cold now and compressor/clutch seem to be working fine - except for non-cycling. I know there is a switch on top the dryer that has something to do with clutch cycling, but I can't find any info on how it works or what it's pressure on/off is. Even looked in the factory service manual and it says basically nothing about it....

 

[mc360]

How cold are we talking? My 99 civic used to freeze me until my turbo waste gate melted a hole in the line,Since replacing it and recharging with a 30lb tank and an ac manifold gauge set to proper amount it won't blow any colder than 55 degrees out the vents but my compressor stays running constant. On my girlfriends 98 civic the ac always worked OK but sticking the temp gauge in the vent shows 55 degrees also and when her compressor cycles off you can feel the cabin heat up quickly, I think her compressor is shot.

 

[Racinfan83]

Mine was at 72 today at about 100 degrees out. I put more freon in it since it doesn't seem to matter on compressor cycling and got it down to 60 at the center vent. See what happens now I guess..LOL
I really wish someone would pop on here with knowledge of that cycling switch on the dryer though, I wonder if it is bad. And would like to know if it just comes off without freon coming out of it or if you have to remove all the freon..

 

[mc360]

Ya I'm no ac tech but I have tried and cannot get it to blow colder in any of my vehicles, 55 feels cold with your hand against the vent but in 100 degree weather it takes like 20 minutes to make it comfortable in my car. How are you charging this? I have a vacuum pump, ac manifold gauge set, digital scale for freon and a 30lb tank and I still can't get it below 55. Think the issue with my car is I didn't replace the drier when I had a hole in the system for 3 months.

 

[Racinfan83]

Not near as fancy as all that. I have gauges, a vent thermometer, and cans of freon. I have an old Dodge truck that has a leak through the high side port so I just put rubber over it with a cap and hose clamp. It stays good for a month or so and then I just add freon. I can add to it just by knowing how the compressor cycles since I've done it so long. So I buy lots of freon when its on sale at Menards for like $3.95 a can..lol

 

[mc360]

s**t 3.95 a can that's a steal, around my area they are like 15$ for the smallest can. Need to watch out with the vans they have stop leak oil and dye, in a 12 Oz can you probably have 9oz freon 1oz of oil and 1oz dye and 1oz of stop leak. Also when doing it by the can you will inevitably add a little air each time you connect the hose which will effect cooling

 

[thendi]

Is your evaporator core freezing? I forgot the name of the switch that prevents the freezing by turning off the coil but maybe that's is your problem. Also, installing a better fan will help cool the car better but only 2-5 degrees. I am thinking about installing a Integra condenser on my civic to make it cool better.

 

[Racinfan83]

I don't think so but I guess it's possible. The switch deal I want info on is the one on top the dryer under the power steering reservoir...

 

[thendi]

I think the pressure switch is on top of the dryer and there is a thermostat that usually goes in between the fins on the evaporator core (that is usually the switch that prevents the evap from freezing by turning off the coil). Have you measured the clearance on the coil to make sure it is in spec?

 

[Racinfan83]

Not sure what you mean by "clearance on the coil"???
I have cool air still but gas mileage has gone from 30 normally to 24 or so. So that compressor running constantly is killing me... Last summer it blew cold air and still got 30mpg...

 

[Restotech]

The pressure switch just stops voltage to the compressor coil when pressure is to high or low. Usually when they go out the compressor will not come on at all. THe clearance is the gap between the friction disc of the clutch on the compressor.

 

[Racinfan83]

Ok well then that isn't it.