ben_shafer

Hey all,

My wifed 07 RDX has 92k miles on it and all last year the AC would kick on and off. Yesterday I was getting on the highway with the AC blowing cold as can be and all the sudden it died and started blowing hot air. Today I replaced the AC Relays(both of them) but still, the compressor will not kick in. Can someone tell be exactly how to jump the relay on the RDX? I see a lot of tutorials but I am not electrical savvy so I need to know exactly which two terminals I need to jump in order to get a gauge on the low pressure line to see if I am low on freon.

WellHellWtvr215

Hey boss,

So AC systems can be a bit tricky to diagnose. It's also tough to tell you how to go about trying other options as well.

First things first, there's a post in the same sub section that you posted in that has to do with the AC being inoperable, perhaps check that out. Given you mentioned it was working properly right before, I have a feeling it's a compressor problem.

Secondly, although you may have a gauge from what it sounds like, if the system is in fact low on refrigerant, it's not turning on as a fail-safe. The refrigerant carries the lubricating oil as well, so if you do happen to turn it on by other means while the vehicle is running, it could potentially seize up the compressor.

Going about it the way you would like, you need to be electrical savvy, as it would require a multimeter and the ability to relate which pin goes to which wire.

Long and short of it here is, have someone start the car and turn the AC on and off while you're looking at the AC compressor. If when it's turned on, it'll make that click and you'll see the pulley start to rotate as well, that would mean something else is wrong. If it doesn't turn on it's either (a) there's a faulty compressor, (b) there's a potential fault in a few different items not allowing it to turn on, or (c) it's low on refrigerant which would kind of require a shop to recharge anyway. I say kind of due to the fact that aftermarket recharge cans from the store only provide a pressure gauge, but systems are charged off of weight, not pressure.

Sorry man, AC stuff is hard to do on your own.

-Shane

ben_shafer

My buddy who is a bus mechanic was helping me out yesterday. When we turn on the AC the radiator fans instantly kick on but the compressor does not engage, We first tried jumping the relay but that did not work. We confirmed power was getting all the way to the compressor by using a multimeter on the plug to the compressor so I am pretty positive it is not a relay issue. We then gave the compressor a few taps but still nothing. We are able to turn the compressor freely by hand so it doesn't appear to be seized or anything like that.

I guess the only way to resolve this would be to replace the compressor or the coil to the compressor which is crazy considering this car only has 92k miles on it. Wife started looking at the 19 RDX A-spec so I will most likely trade this car in and hope they don't test the AC.

WellHellWtvr215

It pretty much completely narrows it down to the AC compressor. If it gets power when it's turned on, that means it's also good on refrigerant.

Most dealerships will take the car for a drive, test out a few things, make sure it's sound. They may or may not try turning on the AC during said drive. If they do, expect maybe a thousand bucks less than what they would give you if it were operating. But ultimately any dealership is going to lowball you to death anyway.

Good luck!
-Shane

ben_shafer

Found an amazing mechanic (hard to come by these days) to replace the AC Compressor for me. $50 for diagnostic and $515 for labor and oem parts to replace the entire compressor. Beats the $1800 I was quoted at the stealership! Literally watched him on my home camera (he's a mobile mechanic) and he finished the entire job in about 2 hours.

WellHellWtvr215

Killer, glad to hear you're back in action.

rt-man

Damn, I'm having the same problem on my '09. 131k miles. Have replaced the relay twice in the last 10k miles. Just recently, kicks off and on intermittently, like the OP said. And its hot out. Goodbye, little RDX. Was fun while it lasted.

WellHellWtvr215

I'll sell you mine if you want to hold on to your car. I pulled mine off completely (condensor, lines, compressor) simply because I never use it. I'm more of a windows down all the time type of guy, even when it is hot out.

I'm about 98% certain it still works, but again I never used it. Let me know

-Shane