A/C pressure moving???

[97splorer]

My A/C doesn't work and I checked the pressure while running on full blast and the system cycles on and off every 5 seconds or so. When it cycles, the pressure fluxuates from 45psi to 25psi. And the system is still blowing out warm air. WHat could the problem be?

 

[Glacier991]

The cutout is set for about 25 psi. That you reach it so quickly suggests you are very low on refrigerant. Probably adding refrigerant will solve your problem, of course you still have to wonder if you have a leak somewhere. Adding refrigerant is a DIY project. Might want to add refrigerant containing dye, and hunt for that leak while you are at it.

Happy Exploring

Chris

 

[MrShorty]

Any hints for using that dye? I've put some in and can't find the leak in my A/C system. It was a UV dye, and I'm using a standard incandescent black light bulb. It's been several months since I put the dye in, does the dye disappear over time? The cans with the dye say to not put any into a system that has already had dye put in, so I don't want to just put more in without knowing if that is the right thing to do. Also, how is the best way to get at the evaporator core to see if it's leaking?

 

[Kamaaina]

The best way to find a leak is to use a "sniffer". Using a dye is okay but how do you find a leak if it's in an inaccessible area? To check an evaporator stick the sniffer probe in the water drain opening at the bottom of the case (located behind the right front fenderwell). Freon is heavier than air and will naturally find the lowest point in the case. Finding a leak there is the kiss of death!!! Do you notice any icing on the lines & hoses? If so, then there's a blockage at that point usually from moisture in the system freezing up.

 

[Glacier991]

Kamaaina is right, there are some leaks dye is nearly useless on (compressor front seal and evaporator immediately come to mind). The good thing about DYE is that for the leaks it may help detect, it can be easy DIY. Sniffers are not in most DIY toolboxes, but when you have one of those leaks, sniffers can detect such SMALL leaks and in places you could never see DYE in that it is the FAR superior way to leak check.

Happy Exploring

Chris