ewgoforth

Hi,

The compressor on my wife's Odyssey isn't turning on.

I've tested what I believe is the AC compressor relay. On the fuse locations page of the owners manual, it's below fuses 15 and 18 in the primary under-hood fuse box. It has a snowflake diagram on the legend on the fusebox cover. It tested ok. It clicked and I got continuity on the two wider terminals when I applied 12 V across the two narrower terminals. I also checked the 7.5 Amp fuse #12, I believe that MG clutch is the compressor clutch, and the #9 30 amp fuse labeled condensor fan. These two fuses both had continuity.

There's also another relay above the 17 and 19 fuses that has a legend of a radiator with fan and a snowflake. I believe this is for the secondary cooling fan that comes on when the AC is turned on. I don't think I really need to test that.

I connected the alligator clip on my test light to the positive battery terminal and touched it to the right narrow terminal on what I'm pretty sure is the AC compressor relay socket in the fusebox and it lit up, so that's ground. I then reattached my alligator clip to a good ground and touched the other narrow terminal on what I'm pretty sure is the compressor relay, it didn't light up as I would expect when the AC was on. So it appears that my relay isn't getting triggered. I think it's a problem with the thermostat or something like that. Any idea what to try next?


-Eric

ewgoforth

I jumpered the two output terminals in the fusebox for what I'm pretty sure is the AC relay and the compressor didn't turn on, which really surprised me.

Maybe the compressor is bad too?

-Eric

microcraft

Start right at the compressor and apply 12V to it. If the clutch engages, that shows that the clutch is good. Don't leave it on too long, (see below)

Next check the AC pressure switch. If you system is low on Freon, it will disable the Compressor from kicking on preventing it from getting damaged.

You will/may need a set of gauges to determine if you are low on freon. If not, then suspect the AC Pressure switch

-mc-

Accordman1

Agree with mc. You will want to borrow or rent a set AC manifold to check both low and high side pressures to make sure your freon level is full and no leak. If it is low, repair the leak first by using a dye to detect the leak. You can use the same AC manifold to safely charge your AC freon but do not overcharge. It will destroy the compressor if the pressure is too high. If freon is full, borrow or rent a code scanner. If it is the pressure switch or temperature sensor, there will be a code from the scanner. Depending on what DTC you got, you just have to replace the right part.

EK FLY

applying 12 to the coil wont give u the entire scope of the situation ,

star with very simple easy task .turn ac control to on /auto , see if you are getting 12v to compressor if that's the case turn off engine , unplug compressor connector , and check ctor ontinuity from comp. case to comp. connector , this will eliminate the possibility of a bad thermal protector , then after all that star checking pressure

samhfoster

Ok I apoligize if there is already a thread for this and for my stupidity. The ac started blowing warm air on my 05 odyssey. After checking I realized the compressor isn't coming on. I checked fuse. Was good. Now the fan speed will not change its constantly on high and also when I turn it off fan keeps blowing. I'm mechanically smart but electrical dumb. Can someone please help me with what to do now?

ewgoforth

Probably start testing relays as I did. I'm a little vague on what my troubleshooting steps were, but I changed the compressor clutch solenoid (I think that's what its called) and it fixed my problem. There's more detailed info on odyclub.com. It's the electromechanical bit that engages the clutch. I also changed the clutch since the van had 150,000 miles on it. You need the special Miller snap ring pliers to do it. They retail for $200 but you can pick them up on eBay for 15 - $30. Look for my user id on odyclub.com. I think there's more info there. That's where I found instructions for changing the compressor clutch without removing the compressor itself.

jlk16188

check to make sure you havent leaked out all of your pressure in the system. Mine leaked from the o rings on the compressor. There is a pressure switch on the system what will not let the compressor turn on if there is no pressure in the lines.