Hi all,

The AC is no longer working in our Escape and hoping to get it sorted out as it’s getting tougher to drive with the summer heat.

I confirmed the compressor clutch is not engaging. However if I jumper the relay the clutch will engage. I tried swapping relay with another (lift gate I think) but it made no difference. I ended up getting enhanced diagnostics with the OBD fusion app and it’s returning the code P0-645-00 (A/C clutch relay circuit).

Note: I also replaced the transducer and oddly the ac began working for about 10 minutes before dying again.

I’m sort of lost at this point and wanted to see what else I could check before taking it into a shop. My thought is to start checking wires. Or buy a new relay.

Any suggestions on what to check next?

 

Without a set of gauges to tell you where you stand refrigerant wise, you are chasing a wild goose !

There is a high pressure and low pressure switch in the system to protect the compressor. jumping them can get you into trouble .


If you suspect there is insufficient refrigerant in the system you could verify that by checking the low pressure sw. It will be OPEN.
It will have power in, but no power out.

The relays in the system very rarely give any trouble. Because we don't know about the switches being open we start chasing relays.
Hopefully this will save you some time, trouble and $$.

 

thank you for taking the time to reply!

what’s interesting is I decided to check that low pressure switch again and there is no continuity.

If I understand correctly that switch should be closed if all is working properly. It was a cheap one off Amazon.

I’ll start looking for some gauges.

 

Pull

Pulled These codes from the enhanced diagnostics. Not 100 percent sure how to interpret or if there is enough information here to tell anything.

 

You checked the low press sw and found it to be open. Do you have power to it? A refrigerant charge that is too low to close the sw could give the problem you presently see.

The majority of the time, the A/C relay just handles the high current the magnetic clutch on the compressor requires .The relay needs to get it's signal from the pressure sw circuits.

 

I had the car off so I don’t think there was any power to it, unless there was some residual power I’m not aware of.

if it ends up being low refrigerant, it won’t take a charge until the compressor is working right? What would one do in that situation?

 

You start with adding refrigerant to the low side, it will take it if low and the compressor should start cycling.

If the system is that low , one can will not be enough.You may need at least 2, 1lb cans.
The correct thing to do is find and repair the leak, we all have a part in keeping our environment clean.
It will save you $$ in the long run.

 

tried adding some refrigerant to the low side but I don’t think it’s taking. I spent about 10 minutes filling and the can still feels the same weight. It feels pressurized because when I remove the charge hose you can hear the air discharge briefly as you normally would.

 

Are you sure you had the fitting from the can to the low side ALL the way down so it depresses the valve core on the low side connection?

 

pretty certain, but I’ll try it again to make sure