First post, I hope I'm in the correct forum section.


2009 Accord EL-X, 90K miles. Air was very cold last summer. Vehicle parked all Winter, but started monthly and AC cycled on for a few minutes every now and again. Couldn't tell if it was working in 14 degree air temps!


I was going to put the car in service this week and the air blows hot. Bought one of the recharge bottles/hoses.


The gage jumped to 100 PSI on the low side when connected. In the red zone on the gage.


I went over to my 2006 CR-V and the gage read a normal 40 PSI (air blows cold in the CR-V) and I gave the CR-V a quick shot to see if the bottle was working correctly. It was.


Fuses checked on the kick panel. Both AC fuses were good


Any advice on what I should be doing next? Do I have a failed component in the system?


Thanks in advance for your help.

 

The A/C is a somewhat complex system. The one thing that you can check with the car off is disconnect the wire to the field coil and using a jumper wire manually jump the field coil wire to the positive terminal of the battery. If it clicks, thus engages, then it is likely not the problem. Also with the engine running and the A/C off look at the clutch assembly. It should not be spinning, if it is then the clutch assembly is probably seized due to rust build up while sitting. If all checks out fine then it gets a bit more complex as far as diagnostics go.

Welcome to the HAF site. There are lots of great people here that will do what they can to help you.

 

Thanks, Turtlehead! I'll unplug the clutch lead and jumper it to check for engagement. I'm in N.E. Ohio and rust is an issue to consider.


I should mention that I'm familiar with 100 PSI from the tires on my racing bikes and when I cracked the low side valve for a quick verification of the gauge pressure reading it sure sounded like about 100 PSI venting.


The AC worked perfectly last Summer and Fall. A clutch failing to engage would not cause the low side to spike, would it? Conversely, would a clutch stuck in the engaged mode over-pressurize the low side?


I'm a fair shade tree mechanic, but I have never had to work on an AC system before.

 

Once the a/c turns off, the high and low pressure sides will equalize. As a rough estimate, the pressure with the a/c system turned off is around the outside air temp. My parents still live in that region, and they said it is in the mid-80s right now, so your static pressure is ok.

One quick test to try is to start the engine up when cold and turn on the a/c. Let us know if both fans on the radiator turn on.

Your car should have a self-diagnostic procedure for the hvac system. I'll take a look in the shop manual I have and post shortly.

I'd highly recommend purchasing one if you do DIY work. You can buy it for ~$22 at automanualsource.com, download it as a pdf, and it is well worth the money.

 

I think you know this, but do not add any R-134a to your system. It sounds like it is charged and overcharging is dangerous.

Is this a V6 or 4-cylinder accord?

Here is a link to find hvac codes I made a while back. This may also help narrow down the problem.

https://www.hondaaccordforum.com/for...-code-s-34589/

 

Thanks for the diagnostics information, PAhonda. I'll print that out...my climate control center looks the same as the one pictured. I'll see if it throws any codes tomorrow, as well as test the compressor clutch.


The Accord has the 2.4 4-cylinder. Will compare clutch rotation and cycling with the 2.4 CR-V. Yes, it hit 87 degrees here this afternoon. I did not hear the compressor cycling when I ran the Accord, but the CR-V cycles pretty smoothly and the engine sound barely changes note.


I'll check to see if both cooling fans are coming on also.


Good info about both side equalizing at shut down. I am learning a lot here.

 

I could not get the diagnostic program to throw any codes.


A jumper wire to the clutch from the battery positive terminal kicked it in with a solid 'clunk' and I could see the solenoid move the clutch plate with the engine running or not running.


With the jumper in place the AC blew cold.


When the jumper was removed the air temp returned to ambient air temperature.


Both radiator cooling fans were running.


Engine changed RPM's and note just a little when the AC was cycled ON or OFF from the control panel with or without the jumper in place.


Any advice on the next step I should take? Again, thanks for the assistance!


Edit: I'm going to pick up some new fuses this morning. I've had blown fuses that looked good in the past.

 

There are a few posts I put in that writeup, so make sure you followed the procedure on one of the later ones. That shop manual I referenced will have that information in there.

When the a/c is not working, do both compressor fans turn on, and does the clutch not engage?

Do you have a volt meter? Do you know how to test for power and ground?

 

"When the a/c is not working, do both compressor fans turn on, and does the clutch not engage?"


Correct. The two COOLING fans run with the air 'ON'. One runs with the AC turned off.

"Do you have a volt meter? Do you know how to test for power and ground?"


Yes. I have a VOM. I tested the AC and the ACC fuses in the kick panel for continuity. Both tested good.


Checked for voltage at the compressor plug and it was zero for all conditions. It appears I am not getting voltage to the compressor clutch for some reason.


I'm a real rookie when it comes to this stuff.


Tomorrow I'll check for voltage at the fuses and continuity from the fuse to the clutch plug.


I used the 03-06 Non-Nav procedure as the control panel is a match to mine. I push/held the AUTO button and then pushed/held the OFF button...both depressed for 1 to 2 minutes. Nothing. No codes.


I'll retry that tomorrow.

 

Just wanted to check about the electrical testing.

A better way to test fuses is to ground you black volt meter probe (any bare metal bolt will work). Set the meter to measure voltage, then touch the red meter lead on the metal tab on each side on top of the fuse. Both sides should have 12V. If one side has voltage and the other no voltage, then you have a bad fuse.

For the a/c, the next place I would test is at the a/c compressor relay. It is in the fuse box under the hood. If the diagram on the fuse box cover doesn't show the location, let us know, and we will post a picture.

Unplug the relay. There should be two metal pins on the relay and two copper pins. The two copper pins provide power to the compressor. The two metal pins are the control for the relay.

This testing is done on the fuse box with the relay removed. The slot for one metal pin and one copper pin should have 12V with the key in the II position.

The other metal pin will be open to ground when the a/c is turned off and be closed to ground when the a/c is turned on. The other copper lead goes directly to the compressor clutch.

Let us know what you find. Another simple test would be to swap the a/c compressor clutch relay with the a/c compressor (or condenser) fan relay. The compressor would work while the fan would not work if you had a bad relay.