a/c compressor makes clicking noise

[PBFreeland]

sss

[shorod]

That depends on why it's clicking. Have you monitored the clutch to see if the clutch disengaging and engaging is the source of the clicking? If so, and it's cycling that frequently, I think you have an R-134a charge that is out of specification.

Who replaced the compressor? Was the new compressor already loaded with an oil charge?

-Rod

[shorod]

Then I suppose the next step is to look at the compressor clutch and see if it is the cause of the clicking [Hmmm, I feel like I've typed this before....]. If the clutch is shutting off, then kicking back on 4 seconds later, you probably wouldn't notice an increase in the vent temperature that quickly. But if it's truly shutting off every 4 seconds there is a problem with the system. Either the charge is not correct (could be over or under charged) or the clutch field coil is struggling to keep the clutch engaged. The latter could be due to too many spacers in the clutch.

Are you quite confident the noise is under the hood rather than in the cabin? Determining the source of the noise may go a long way in helping figure out what's happening.

-Rod

[shorod]

That depends on the shop and if the parts manufacturer will reimburse them for labor if the part is in fact defective.

Can you confirm the on/off duty cycle of the compressor as 4 seconds on, 4 seconds off? If it's truly only on for 4 seconds something definitely isn't correct but pressures or pressure switches would be my initial suspects rather than the compressor or clutch.

-Rod

[shorod]

Is the pressure switch on your Explorer a 2-wire or 3-wire switch? If a 3-wire then it does both low and high pressure. If only a 2-wire, then there is probably another pressure switch for the other pressure extreme.

There should be a shrader valve under the switch so you won't lose your R-134a if you unscrew the pressure switch.

-Rod

[shorod]

Nope, the one that the switch is screwed on to.

-Rod