The A/C system in my 94 accord lx doesn't work. It appears to be fully functional except for shot bearings for the compressor flywheel. I'm going to replace the compressor this Friday. Today I turned the fan for the cabin and absentmindedly turns the A/C switch on. I felt instant drag on the engine. I know what you're thinking, bad bearings, of course there's drag on the engine. I would agree but the air conditioning has been bypassed on the serpentine and a smaller belt installed. I currently do not have a fuse for the condenser fan. The compressor is plugged into the harness though. It appears that my A/C is acting the parasite and pulling power from the ignition, enough to cause a noticeable decline in engine function. Would this be normal if the clutch engages but the compressor doesn't turn or am I looking at a massive short? If it is a massive short, where would the best place be to look? Does the A/C run directly from the alternator or is it buffered through the battery like the ecm and other delicate electrical systems.

 

That "drag on the engine" is probably the electrical draw of your cooling fans turning on. Every Honda I've owned of this vintage does this. Often you will feel the engine vibration increase noticably through the steering wheel.

Honda's electrical system seems to be more sensitive than other makes and you can really feel the draw of electrical accessories. Although it would not be normal if your ignition is cutting out.

 

Thanks, I didn't think about that. The engine wasn't up to temp so the fan wasn't on till I hit the switch.

 

You could always have your battery and alternator checked for free at a place like AutoZone and see if the alternator is getting weak, thus causing more upset when things turn on and off. Just a thought.

 

No parts store in existence has a way to properly test a Honda alternator.

Totally agree with maso.

 

Wouldn't be the battery, it's brand new. I don't think it's the alternator either. I get strong electrical everywhere else in the car. Most electrical problems I do have are cured by unplugging than plugging back in the connector reaffirming the connection (rubbing through a thin layer of corrosion)

 

I have noticed this drop in engine power with AC on my manual 92 Accord EXR too. Turning on AC changes the drivability a bit, I need to push the gas pedal further and be more careful when changing gears. It idles OK with AC on.

AC works but probably does not cool as much as when new, I am guessing it needs a AC coolant change or top up and maybe the AC radiator fins need to be cleaned for better heat transfer.

I will just assume my car is acting normal as per masospaghetti's posting.

 

When the AC compressor clutch engages it draws power through the serpentine direct from the crankshaft. Slight power loss when you turn on a functional AC is normal. Your engine has to give a little more physical exertion to run your AC. If its more than just a little power loss, replace your condenser or atleast get a bypass belt in place to isolate your AC from the serpentine. If the compressor is pulling too much from the engine, soon your belt will start slipping and eventually break.
If your AC is holding pressure you shouldn't need to replace the coolant. The most common reason auto ACs lose efficiency is too much coolant in the system.

 

If your saying there is no belt to A/C compressor, then turning on the A/C is technically a short, and I am not sure on a 94 but engine may not "idle up" when A/C turned on if compressor and /or condenser fan is not running, try unplugging compressor relay. 94