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Hi all haven't been on for a while but new issue my AC won't work the compressor is not seized it just wont come on checked all the fuses and tried to check the wiring but it is so short then it go's into the main wiring harness is there a way to see if it is the compressor or not some way to test it?
Thanks in advance it is on my 2002 explorer 4.0l vin "E" eddie bower
The A/C compressor clutch will not attempt to engage the compressor if the pressure switch measures the system pressure to be either too high or to low. Typically the cause of the symptom you describe is a low charge of the R-134a.
Unfortunately if you don't have a manifold gauge set it's difficult to confirm whether the charge is either low or high. The refrigerant is what carries the lubrication for the system through the components so you don't want it running very long if the charge is low or if the system is empty. Otherwise you can attempt to jumper the pressure switch to confirm the clutch is working properly, but only for a very short duration, long enough to see the clutch engage.
I also would like to caution against just buying a can of R-134a with a gauge on it and trying to stuff more refrigerant in the system. The performance of a modern A/C system is quite sensitive to being overcharged as well, which is easy to do when using the small cans.
Thanks Shorod i will check it out do you think the large cans of r134a with the gauge on them will let me know what i need to know? or is just the best thing to do is let someone that has the machine do it? but cost is a big thing for me i am a poor boy lol thanks again
ok looked for it but there is 2 of them i am guessing? a low pressure switch, a high pressure switch, and a cut off cycling switch what one do i check and hwere are they on the truck? i think i found the one but not sure Thanks
Hey thanks i found it and when i jumped the plug the compressor came on so either it is a bad switch or low r134a i think i will start with re-filling the r134a thanks for the help and will update later after i try and see what one it is thanks again
Well, by "small cans" I was referring to anything less than the 30+ lb tanks used with professional systems.
With the pressure switch jumpering that you did above and the results, it does sound like it's pretty likely that you are just low on R-134a. If the system is not completely empty and you want to try saving as much money as possible, you can start with 1 can with the pressure switch reconnected and the engine running, HVAC set to A/C. Start to fill the system until the compressor clutch engages and the compressor runs. Shut the valve on the can at that point and check the temperature from the vents. If it's somewhere less than 40 degrees, that might be a good point to stop and disconnect the can. You don't want to overfill the system.
If very quickly afterwards the A/C stops working again, or one can is not enough to get the compressor to engage, you have a leak large enough that you really should save to get it fixed properly.
Thanks Shorod isn't there something i can put in it to check for leaks?i used the cans but it has a trigger and a pressure gauge on it and it was between the lines where it said to be after setting it but want to see if there are any leaks and get them fixed the truck sat for 2 years before i bought it so it might have leaks
Some of the cans of R-134a have a leak detection dye in them which, when used with a UV light, can help find leaks as long as the leaks are in an area that you can get to with the UV light and be able to see. That won't help much if the leak is on the back side of the condenser or in the evaporator core, etc.
Also, since the refrigerant carries the oil for the system, if there is a leak that has been leaking for awhile there will often be an oily appearance, usually that's dirty too from collecting dust and dirt, around leaks. If you follow the system and find one or more spots that are really dirty relative to the areas around it, there's a good sign there's a leak in that dirty area.
