Hi there. Been checking out your site, its great! I bought a 2006 oulander for my wife brand new. It has been a great car for 115,000 miles. Now the a/c does not work. I replaced the cooling fan controller but same deal. The a/c light on the interior does not flash, it just stays on when you push it. I am thinking the pressure switch relay next. I am hoping its not the compressor/clutch but I have a bad $500 feeling. Help! I hate replacing parts on guessing!

 

Does the coompressor cycle on and off? Check the connections and see if there is an oily-greasy buildup around them.

If the compressor does not cycle on and off, there is nothing in the system (R134a) to compress.

 

I worked on it last night. I disconnected the 3 wire plug in the a/c piping along the firewall. Started the car, pressed the a/c button, then checked each of the 3 wires for power. There is no power at any of the 3 wires. Does this mean the a/c controller is bad? Thanks in advance for your help!!

 

Plug the connector back on.

Start the engine.

Turn on the AC.

Does the clutch engage and disengage the compressor.

These are CCOT systems-cycling clutch,oriface tube-systems. The compressor clutch has to engage to build up pressure, then it cycles off when max pressure in the system is reached. There is a switch (High side cut-off switch) that will turn the compressor clutch of. When the pressure in the system drops, there is a switch(low side switch) that will re-engage the compressor clutch.

The system works on pressure and temperature.

If there is an oily buildup on the hose connections, this means that the refrigerant (R134A) has leaked out of the system.

The sure way to check the system is to pull vacuum and see if it holds. If it looses vacuum, there is a leak in the system and you can put all the refrigerant in it you want, but it will leak out.