[kingston73]

Hello, somewhat new to the forum. I tried running my AC today and nothing, the compressor belt is tight and the pulley spins, but when I press the button in the cab there is no change. The manual says there should be an audible "click" and the center of the compressor should spin, but it does not do either. Where should I start with troubleshooting this? It worked fine last time I ran it, but I haven't turned it on for a few weeks.

2.7L 2001 engine

 

[nim]

a/c's have a pressure sensor near the dryer cylinder and prohibits operation of the compressor with low or no freon pressure. it could be a bad sensor but they rarely go bad. check the a/c fuse, check wire connections to the sensor, check a/c electrical connection and wires. barring that, you're probably low on freon or compressor is seized. i guess you could also check voltage of sensor wire as well. it could also be a bad switch in the cabin (see if light is on switch).

 

[kingston73]

The AC button in the cab lights up, and the 10A fuse in the engine compartment is good. The compressor center rotates if I spin it by hand. I looked at and followed any/all wires I can see that are connected to the compressor, no obvious cuts but I don't have a multimeter and wouldn't really know what to do with one anyway so that's about the extent I can diagnose any electrical problems. When looking in the sight window of the condenser/drier (the cylinder up in the front corner, don't really know its proper name) am I supposed to see anything? It just looks empty, no bubbles or liquid or anything. If I just go get a recharge kit, is there any way I could screw things up, or is it pretty straight forward?

 

[Taconator911]

I don't know if there is any truth to this but what I heard is that the recharge kits don't last half as long as if you where to get it recharged at a shop. Therefore you will buy more kits and do more recharging. Now I don't know if this is true but it might actually be cheaper in the long run to not use the kits...not sure though

Anyone out there know a definite answer?

 

[monkeee2002]

I've heard the same, from legit A/C techs, but they may have been pushing for business, who knows.
They told me that it's very easy to get too much pressure into the system, which is very sensitive, and blow seals.

Good A/C techs can also add a dye, which will help you locate a leak.
IMO, it's worth it to have the dye put in (they usually do it for free with a recharge), especially if you think you might be low on freon.

 

[84Cressida]

A/C freon doesn't "run out". If you don't have anymore you've developed a leak. IMO, I would take it to a mechanic and have them use their fancy vaccum/dye and leak detector gizmos.

 

[hilux5084]

Thay are right the refigerant dosnt run out it leaks, the leaks should be found and repaired, if its a very small leak some dye should be added with a recharge to locate the source of the leak major leaks will be evdent by the oil stains left usualy at joins or the compresor shaft seal and will have to be repaired first.
The reason that do it yourself recharge dont last as long is usualy because they may not be the correct capacity, either too much or not enough, this is why taking it to a pro is recomended because they will meter the gas charge to the recomended amount and if oil is lost it has to be replaced also.

Joe

 

[Starman97]

Get a set of gauges, or borrow them from AutoZone, with the compressor off, you should have about 70PSI
on both, with the compressor on, the low side should be around 30 and the high side around 210PSI.
If it's hotter than 85 outside, these pressures will be higher. Consult the shop manual for exact #s

The reason the cans don't last as long is that you have a LEAK!, an AC shop cannot legally refill a system with a leak and they will have to find and fix the leak before recharging. Better shops have electronic 'sniffers' that can detect tiny leaks that might take a year to show up with the dye.

See any greasy spots on the hoses or piping, especially near fittings and valves? Is the compressor clean, or does it have a trail of dirt/oil running down from behind the front clutch assembly?