So, my 2003 2.5L X Type needed a new compressor so I changed that as well as the dryer, orifice tube and condenser. Vacuumed the system and went to recharge it. The compressor never kicked in and accepted no gas. Rechecked everything and it seemed fine. So today I jumped the terminals on the relay and the compressor kicked in just fine. But still no gas was accepted. A real head scratcher. Controls were set to LO. Any ideas?

 

ital. are the radiator fans kicking on when you have the AC button lit on the dash? If the fans aren't running, the fan control module may not be letting the AC compressor cycle on. If the fans start running on a cold car at first start or not when the AC is active then you will have to replace that module. The other issue may be the pressure sensors on the AC feed lines but I can't speak intelligently on how to diagnose those.

hope this helps?

 

Good point on the fans. I'll check tomorrow. However I did bypass the compressor relay and the clutch did engage. And yet no refrigerant was flowing. I'm thinking an obstruction. Could the orifice tube I replaced be faulty? Do we really even need that thing in there. What would happen if I omitted it?

 

Ital, you absolutely need the orifice tube in the system. It acts as a simple non mechanical flow regulator for the R134 gas separating the low and high pressure sides of the system. It also changes the R134 from a liquid to a gas that will absorb the heat from the car's interior. As long as you have the correctly sized one for the system (the holes in the end of it are specific to the charge weight in the AC system), there shouldn't be any issue there. If you bought it with the compressor or the kit, it should be correct.

Here are some other thoughts that may be causing issues in the system:

• Did you flush the entire system before you replaced any of the components? If you had pieces of the failed compressor still in the lines. they could easily clog the lines and not allow the R134 to fill the system.
  • Also, junk in the lines can easily clog the new orifice tube. When drawing a vacuum, you may pull junk into the orifice and clog it.
• Did you swap out the schrader valves from the fill ports? When I worked on my system last, they were leaking and allowing R134 out and also not allowing new gas in. I learned the hard way that when drawing a vacuum, the fittings seal them, as soon as you disconnect everything falls apart.
• Double check the condition of the fill valve that you are connecting to the cans of gas. Mine wasn't completely piercing the resealable top and r134 wouldn't flow. I assume you got gas when you purged the fill lines but if not... (?)
• I'm sure you've double checked that only your low side valve is open when you're adding the 134? If both the high and low are open, my understanding is that the refrigerant can turn to a liquid and do bad things inside the compressor (smarter AC folks, please correct me if I'm wrong here).

Please note that I'm not an expert, just a youtube student like a lot of us here. So again there may be an issue with one of the sensors on the system as well...

 

Well said. Yes, only low side was open. I did purge the fill valve at the fill line before opening to the AC system and I did a new vacuum just in case. The schrader valve are interesting but I think I should pull the orifice tube and check it out. Maybe even replace it just in case it's faulty. What are you're thoughts?

 

If gas hasn't gone into the system, opening the orifice tube area up is only a few minutes and certainly worth checking. It's unlikely it's faulty out of the box, but its possible? Since it also acts as a filter, any junk in the system can settle there and easily clog it. You will have to pull a vacuum again but if you have the tools, why not?

I would also really recommend changing the Schrader valves. They aren't expensive ($10?) and certainly cheaper than the time or r134 wasted if they are leaking / jammed. Most auto parts stores have them on the shelf and they aren't that unique so you shouldn't have to wait to order. The kit usually comes with the tool / key for them so you shouldn't need to track anything down to do them. If you do need to swap the orifice, pick them up at the same time.