I had ac problems back in Oct. Living in Indiana I figured I should fix since I will be needing in a couple weeks. Back in Oct I applied voltage to the terminals where the blk and white wires are connected on the compressor (looking at schematic this is power to engage the clutch), and it engaged the clutch. So I knew I was not getting power to the clutch. I replaced the relay and checked all fuses (were good). I read where the flow sensor is notorious for going out so I thought that may be my issue, not, I just replace it and it is still not engaging. So I applied power on the some two terminals on the compressor as before and nothing happens. Now I am questioning myself if I actually tested it in Oct or it was just a dream, lol. Anyway if I put 12v dc (+ and -) while the car is running and calling for ac shouldn't the clutch engage the compressor?

 

There is a safety switch which cut of the 12v to the AC clutch. This switch gets activated when the refrigerant pressure falls below a specific value.

Salim

 

Yep, your first troubleshooting action with any HVAC system should be to determine whether your refrigerant level is up to spec for your particular vehicle.

 

I have 80 psig static pressure. Since the system usually runs around 35 psig I assume the switch should be closed. My question was one, am I applying voltage at the proper spot and two shouldn't the clutch engage when I apply voltage?

 

This may or may not help but some had success adding a cheap magnet to the flow sensor external switch on the compressor. See this thread starting around post 84 if you want to skip the technical stuff, or read the whole thing.

​​​​​​https://www.clublexus.com/forums/rx-...olution-6.html

 

I did try the magnet on the original sensor and have not tried it on the new sensor I will try tomorrow.

After looking at the schematic (https://portal-diagnostov.com/en/202...ring-diagrams/) I have a couple questions as I believe I was powering the wrong terminals. If I put 12v on the blue wire on the compressor this should engage the clutch?
What are the sol- and sol+ (wht/blk and blk wires)?
What is the lock sensor?

 

Could someone tell me where this F50 connector is located and how to get to it? I would like to ensure I have 5v on 30 Br and see what I have from the flow sensor on 7 Yel.

 

I checked at the flow sensor and have 5.0 v on black and 4.47 on the red wire. I had a powerful magnet on the sensor and it did not change from 4.47. I also tried to jump black to red and nothing... At a loss

 

I just had the same problem in our Acura TL. AC Clutch was not engaging. It was a bad AC clutch relay. Relays can get stuck over time. Took me 5 minutes to swap in a new relay. Not sure if the RX has one but if it does, I would check that as well.

 

See if you can get hold of circuit diagram to enable you to do logical debug.

Salim