My A/C started to give me problems about 2 months ago, whenever the A/C was on the car started to idle, going up and down on the revolutions but the A/C was still cooling. The idling started to get worse and everytime it idled there was a “clack” noise coming from the engine (it sounded like the compressors clutch wasn’t sticking). I called a friend who’s a mechanic and he told me it may be was the A/C sensor that wasn’t working but now the A/C is not cooling. I took it to a Honda dealership to see what was their opinion and they said that the problem is the computer that the signal from the computer to the compressor is not going through, they said they bypassed the signal and the car stopped idling. They also added that the engine’s fan is not working and that may be another problem. They recommended to buy an used computer and fan and install them and that may be work. I’m a little hesitant and needed some advice.
Not sure, but my 97 would idle low when running AC and then I cleaned the filter on the intake and it got better. I am not sure what the filter is called but its on the back side of the engine on the intake.
If the fan is not working, do that first. I really doubt that the computer is the problem. The computer does control the compressor clutch, but it uses a bunch of inputs to decide when to turn the compressor on and off. It could well be that with the fan not working, the computer is not programming the compressor on.
I do not understand “they said they bypassed the signal and the car stopped idling.” That doesn’t make any since to me. Did they mean that the idling problem stopped and the idle returned to normal? Or did they mean the engine died?
The signal from the computer does not go directly to the compressor clutch. The signal from the computer is merely a path to ground for the compressor clutch relay. The actual voltage to the compressor clutch goes directly from the fuse block, to the relay contacts and then to the clutch relay solenoid. This relay could be the problem. But if the fan is not working, the computer is probably not supplying ground for the relay so it must be fixed.
There is also a relay and a fuse for this fan, those should be checked first. When you select AC and a fan speed, ground is provided for the relay coil. This energizes the relay and it sends 12v to the fan. First check the relay and the fuse. There are two fans and there are two fuses and two relays. Both fans have to work.
My experience is that the fan is probably bad. I would not get a used one, I’d get a new aftermarket fan. I got one for my 97 Accord for around $112 on the internet but I don’t remember where I bought it. I use rockauto and autopartswarehouse a lot so it might have been one of those.
Are you doing this work yourself. If so, let me know and I will give you instructions and location information.