2003 Honda Accord Compressor Clutch not Engaging... It's Hot in Memphis right now...

[2003 Honda Accord]

I was sitting at a stoplight yesterday, when the A/C stopped blowing cold air. When I look at the compressor, the clutched in not spinning/engaging once the A/C butten is pressed. I checked the fuses and electrical lines running to the compressor and they look fine. I tried checking the freon level, and the gauge was reading 120 PSI !! on the low-side line. It was so high, that no additional 134A can even be added. I pressed both the valves on the high and low side lines, and there is freon in the lines.

Any thoughts on additional tests or diagnoses?

[jeffcoslacker]

When the system is at rest (compressor not running) the high and low sides equalize. 120 psi is not excessive for a static reading.

When the compressor starts, that will drop if that was the low side reading.

Chances are it is just low enough on charge to disable the compressor. You can force the compressor clutch to engage a number of ways, but I'm not gonna recommend it (nudge, wink)

Possible the relay for the system is stuck too. If you can locate it in the underhood power center, and have one of the same type in there, you can swap them and see what happens. If you don't have a donor, try tapping the relay lightly on a hard surface...sometimes that'll wake them up if the contacts are stuck for some reason. If that works, I'd buy a new relay.

I'm assuming you are working with one of those 134a suicide hoses with gauge that shows low side pressure?

You can try tapping a can, hook it up to the port, and with the engine running and A/C on MAX, spray your condensor with water from a hose (this cools the condenser and lowers the static pressure) and try valving in some 134a. If it sucks it in readily, the compressor will probably start within a few seconds. Once it starts, it will devour the can pretty fast. If it doesn't, or pressure continues to climb with the comp engaged, there is a blockage or something.

[jeffcoslacker]

PS I've seen some pretty scary low side pressures and haven't burst a can yet. There's a safety relief knockout on the bottom of the can...just keep that pointed away from you.

It probably would make you piss yourself though. I've blown a safety relief on a receiver/dryer before. Sounded like a firecracker

[jeffcoslacker]

A little more...I did a quick check because it's been a while since I did A/C service regularly...I found 85-105psi as normal static pressure for 134a systems....

Have you added to it before? It may have been running an overcharge and might have had a high side kick-out and is now disabled to protect the system...I'm not sure exactly how advanced the control system is on your car. Cars I've seen that are capable of that have an indicator that displays when the system goes into fail safe....

I dunno. Hopefully someone here can tell you more.

[2003 Honda Accord]

For clarification on my part, the low-side was registering 120 PSI whether or not the A/C was on. If it changed any, it was so slight I couldn't tell.