Hey guys, I have a wierd problem that just started happening.

When im driving with the A/C on, mainly on Max A/C, once I hit 50mph or so the air just cuts off.. It just stops. Once I let go of the gas it comes right back on. When its on A/C it doesn't do it very often, but it occasionally does cut out while going above 50mph.

Its also not feeling as cold as it used to feel. It still does a good job, but im starting to wonder if the compressor is getting ready to give up the ghost.

Any suggestions would be appreciated..

 

Probably low on refrigerant. You can get a guage and a can of R-134A for about $30 so once you put the guage on it you will know if its low.

 

+1 on the low refrigerant. Evap temps will get lower on max a/c since on that setting you are recirculating the cab air. On the a/c setting you are taking in outside air (hotter) and cooling it down. Low refrigerant would be more sensitive to the max a/c setting (imo)

However don't just throw a can of refrigerant in and go, like MANY people do (i cringe every time i see it). Do at the very least get a can with a gauge, or an external gauge and watch the low side.

 

Great info guys

 

Okay, any particular brands? or just any ol can of R-134A. Also, where abouts will I hook up this thing too add more refrigerant, and where exactly do I want the gauge reading?

You know I got to thinking, is this common to have to add in some refrigerant, because to me this implies that there could be a leak if its low..

 

If you are going to service it, at least use a thermometer in the vent and cut off flow once the temp stops dropping. I'd suggest 2000 rpm while adding the r134a, med fan speed, not in max/recirc. Then drive it. If the duct temp gets colder than it was at 2k rpm, you're golden. If it goes up, you added too much.

Your problem sounds like a vacuum issue. See if the AC gets ducted to the windshield defroster when it "just cuts off".

 

Hmm ill check on the vacuum issue and get back to ya. Thanks Earl.

 

Earl the man of ac wisdom.


Put your truck in first(L1), turn the a/c on high. Drive, stick your hand on the defroster. I bet soon as you go over 2k for an extended period of time it will cut to the defroster. Which is what its desinged to do if you have a vac leak that way you can still see.


Common problems is a bad line feeding the res or a hole in the res. Its under the air box up in the fender.

GL

 

Now where abouts is the port where I add in more R-134a? Does anyone have a picture of it? Or can just tell me where it is?

 

It's on the hard lines. They have colored caps on them that say "H" and "L." You want to add on the low side because it's before the compressor. Well the fittings are different so there is no way to add to the high side.

 

Passenger side near the firewall. Its a black hotdog shaped tank with a valve on the top.


Make sure you check the pressure while its operating to see if you really need any.

 

Got it. I checked the A/C level and its fine. It does seem to route to the ducts on top of the dash once I go over 50mph. So is there anything I can do myself or is this something I need to take to the professionals?

 

You just need to look at the vacuum lines for holes and the reservoir for holes/cracks.