Question On Automotive A/C (obviously non-valk)

[Steve K (IA)]

My wife has an '03 Ford Taurus.  We had a new A/C compressor installed 2 years ago and a new accumulator / hose replaced less than a year ago.

Everything was fine during the last year.  Now the compressor clutch won't engage.  I checked the A/C clutch fuse.  It was OK.  Replaced the A/C clutch relay, still won't kick in.

I know we have a few Automotive Pro's here.  Is there something I am missing that I may be able to fix?  

It's starting to warm up here and if I can't get it running, I'll need to make an appt. with the garage down the street.

Thanks in advance.  

[jmann]

Check your freon. Some won't engage if the pressure is low.

[Steve K (IA)]

Check your freon. Some won't engage if the pressure is low.

I have experienced that before (low on refrigerant) and the compressor would kick in-and-out.  Since it just plain won't kick in, I didn't think of that.  If that happens to be the case, that would mean it has a leak.  If that is the problem, I'll need to take it back to the place that replaced the accumulator / hose. 

[vanagon40]

I agree with the low pressure.

The fill port is a Schrader valve.  You might want to press it to see if there is ANY pressure in the system.

If you can locate the low pressure switch, you could check the voltages to confirm.

You could check the voltage at the clutch to make sure it is not getting the signal to engage.

With the engine off, you could apply power directly to the clutch to make sure it will engage..

[jimmytee]

Check your freon. Some won't engage if the pressure is low.

I have experienced that before (low on refrigerant) and the compressor would kick in-and-out.  Since it just plain won't kick in, I didn't think of that.  If that happens to be the case, that would mean it has a leak.  If that is the problem, I'll need to take it back to the place that replaced the accumulator / hose. 

If the system is low enough on refrigerant (freon) then it won't kick in. When you've experienced short cycling of the compressor clutch in the past it is because the pressure was high enough to engage, but as the compressor starts and runs , the low side of the system drops to below the low pressure switch cut out point and cycles off. Then ,with the compressor not running, the pressure rises again and the switch makes and repeats the cycle.

[art]

Check your freon. Some won't engage if the pressure is low.

I have experienced that before (low on refrigerant) and the compressor would kick in-and-out.  Since it just plain won't kick in, I didn't think of that.  If that happens to be the case, that would mean it has a leak.  If that is the problem, I'll need to take it back to the place that replaced the accumulator / hose. 

If the system is low enough on refrigerant (freon) then it won't kick in. When you've experienced short cycling of the compressor clutch in the past it is because the pressure was high enough to engage, but as the compressor starts and runs , the low side of the system drops to below the low pressure switch cut out point and cycles off. Then ,with the compressor not running, the pressure rises again and the switch makes and repeats the cycle.

You nailed it. I had the same problems and every so often I would put in some freon an it would be ok. Sounds like all the freon is gone. Must still have a leak.

[michaelyoung254]

The first thing I would do would be to connect a set of gauges, and check the pressure. If it's completely empty, that pretty much explains why the clutch will not engage, and if the systems completely empty, you must have a fairly large leak. If you don't have the equipment to find the leak, you're pretty much going to need to let someone who does repair the system because part replacing can get real expensive real fast.

If there IS pressure in the system, the first thing I would do would be to use an ohmmeter across the clutch in order to make sure it's not burned up. If you don't have an ohmmeter, simply jump the switch on the clutch directly to the battery. The clutch is basically an electromagnet, and sending 12 volts across the clutch should engage the clutch. If the clutch checks out, I think the next place I would start would be the A/C switch panel inside of the car.

[Robert]

Check your freon. Some won't engage if the pressure is low.

 

 

Sometimes the hose connections do leak look for the green dye.

[Jess Tolbirt]

yep, low on freon, or the lo0w pressure switch is bad,, 90% of the time its low on freon,,