Air Conditioning Troubleshooting

**MitchW** · #1 (**permalink**) 04-22-2008, 09:06 AM

The AC in my Verde has never worked in the 3 years that I've had it mostly because I didn't care all that much and there were other things to work on. There are still other things that need work but I figured its time for the AC. The PO had put in a new compressor but its now 3 years old and I know they need to be used to keep them lubed and the seals in good shape.

Are there any guides to troubleshooting this system with simple tools or do I just bite the bullet and bring it to a shop?

Mitch

**torcia** · #2 (**permalink**) 04-22-2008, 03:26 PM

Mitch,

I have been searching for info on the A/C as well. Yours is probably a Behr unit. Behr A/C systems were used in many different European cars during the life of the Milano but BMW is one that comes to mind. I have found several tidbits from the BMW forums but have not figured out if our systems were used on any other marques.

The first thing to do is to see if the clutch on your compressor is engaging or not. Just open the hood and turn the A/C on full cold. You should see the entire mechanism on the A/C drive pulley turn. If the inside of the pulley is not turning then the compressor is not running and you will not get any cold air. The cause of the compressor not running is either electrical or the pressure in the A/C system is low. You can check to see if it is pressure by shorting the low pressure switch. If the clutch turns then you need to visit the local A/C shop and get it checked for leaks and topped off with coolant. If the clutch still does not engage when you short the low pressure switch then it is time to dive into the electrical system. The clutch relay is on the passinger side engine bay and it has a fuse on it so that would be the first thing to check. Then check the relay it self to see if power is getting to it and whether or not the trigger signal is coming from the A/C thermostat.

These are some quick and dirty things to check. If you come across any more info on the Behr system in our Milanos, like a wiring diagram, let me know.

I found all of this stuff out by just searching the web for Auto Air Conditioning.

**MitchW** · #3 (**permalink**) 04-24-2008, 10:13 AM

Thanks for the info, I hadn't even looked to see how you turn on the AC yet. Turns out I've had it turned on for years but it doesn't matter since its not working. I took a look under the hood and I think I found the low pressure sensor in the right front corner of the engine compartment. Is the connector under the radiator hose or is there somewhere else that I can jump it?

mkeith · #4 (**permalink**) 05-02-2008, 10:42 AM

The AC pressure switch is on the receiver/dryer. You'd be much better off it you could get a hold of a set of gauges to see what's actually going on with the systems. The Milano AC system isn't all that unique. If you live in an urban area, a local AC parts supplier will be able to physically match up the system's major components. Most likely, you've lost refrigerant, but without gauges, you're flying blind.

They're really not that much money. Before I was able to buy some nice ones, I ordered a set of el-cheapo R12 gauges through my local O'Reilly store for around $50. The hoses were kinda short, but they got the job done.

By the way, here's a great web site dedicated to automotive AC systems: Automotive AC Information Forum - ACKITS.COM