Rep Power: 0

Ok this is gonna be an a/c question for a 2001 Honda civic dx.. I have checked the freon levels, fuses, tested relays, everything possible!! Finally found out while the Ac clutch won't engage, and that's where I need help. In the underhood fuse box, the Ac relay has power going to it and to the fuse box but when you turn the Ac on the relay isn't being eneergized. It is my belief that this will be a problem leading into the Ecu... Is that correct?? And what can be done to fix this besides buying a bran new $450 ecu

 
Rep Power: 518

Proper diagnosis, rather than guessing at the most expensive part.
(What are you calling an ecu? The PCM?). And you didn't add labor to replace it, nor the fees for programming it.

How about a systematic evaluation:

You said the compressor clutch doesn't engage.
Do the radiator fans still come on when this happens?

Does the interior fan still work correctly?

Got any other clues?
Got any other electrical problems?

 
Rep Power: 0

Ecu/PCM.. Is how it shows on all data... And love and all that is no problem.. I work at a parts store and get very very good discounts and yes all other fans kick on... But run from a different relay... I can jumper the relay and the clutch kicks on an works just fine... I'm pretty positive the computer just isn't grounding the relay... But I don't know what has to happen for it to ground... And what I can do... Options...

 
Rep Power: 518

Got a scanner that gives a datalist?
Second thing I would do is read data, see if there is an AC REQUEST made to the PCM, and then see if there is an AC CLUTCH ON command from the PCM.
The fans generally run any time the clutch is turned on. So the PCM SHOULD be turning on the clutch.

First thing I would do is diag at the clutch relay socket. Be certain of which way to go.
"pretty positive" tells me you don't really know, you're just guessing.

It is REAL SIMPLE to test and be certain. A test light and a little working knowledge is all I need.
Turn the AC on, remove the clutch relay, and there should be 2 powers and 2 grounds in that clutch relay socket.
If you have all those, the relay is bad. Simple.
If any one is not as I said, then there is a direction to go.


Got the correct socket in the fusebox?

Have you swapped relays around? I see a lot of the clutch relays with contacts that can't pass electricity.



Got a wiring diagram for the AC and fans?

 
Rep Power: 253

Putting cheap aftermarket parts in place of good OEM parts is a bad idea. Especially when the OEM parts are good.