AC question - HELP PLEASE - Page 2

ngrome · 06-23-2009, 11:06 AM

Well, when I get home from work (wife has the XL7), I'm going to have to check and see if the compressor clutch is engaging, though I know it's spinning. I took a pressure measurement when it was 90 deg F ambient (yes, it's hot here in Florida), so the rule of thumb that lumpylarry told me indicates this is normal at 45 psi (but it is never reading lower than that on the low side, assuming the compressor clutch is not kicking in)? Is it hard to change a compressor yourself? I've done brakes on a car, but nothing to this extent.

Considering it's still cooling, just not ice cold, and assuming the compressor clutch is not engaging though the compressor is not seized, is it ok to continue running it this way? It's been like this for almost six months since December. I've seen in this forum that an XL7 compressor can cost anywhere from $500 or more, and to replace it at a dealer can be anywhere from $1200 or more with labor. Oh woe is me, that could cost me more than my actual vacation! Just want to make sure I'm not imagining a problem here.

Thanks for everyone's help and suggestions on this thread!

Max · 06-23-2009, 02:26 PM

IF your clutch was slipping, you'd smoke it and hear strange noises as well, so if the unit is cooling (but only marginally) I'd suspect a freon leak resulting in a now low charge condition.

Changing out the compressor proper isn't bad. It's the added need to replace the filter / dryer, ensure the correct oil charge is added, evacuating the system of air and re-charging it to the proper level that requires mechanical (A/C) expertise and unique supporting equipment and tools.

ngrome · 06-23-2009, 06:05 PM

Quote:

Originally Posted by Max

IF your clutch was slipping, you'd smoke it and hear strange noises as well, so if the unit is cooling (but only marginally) I'd suspect a freon leak resulting in a now low charge condition.

Changing out the compressor proper isn't bad. It's the added need to replace the filter / dryer, ensure the correct oil charge is added, evacuating the system of air and re-charging it to the proper level that requires mechanical (A/C) expertise and unique supporting equipment and tools.

Yes, thanks Max. I took another low side pressure reading today after work and it was at around 28 psi, looking normal again. I'm thinking when I took the reading yesterday afternoon, it was around 90 deg F, while it is now 70 deg F when I took the latest reading. I'm suspecting it may have been a leak, and would only ascertain the bitter cold conditions in Chicago last December to contract some seals to let freon escape, because down here in FL, I'm not losing as much refrigerant, just doesn't seem to be cooling as it did before the trip last Dec. Anyhow, if that didn't make any sense, I did run the AC to hear the compressor kick in right after I started the engine, so it seemed it did, though not sure it's cycling as much as it should, again, could be related to the amount of refrigerant (possibly lost). Well, it doesn't warrant me to take it to the shop at this point, at least I don't think so, but I will pack an extra can of R134a and make sure my Triple AAA card is with me and not expired.

Max · 06-23-2009, 09:42 PM

Yep. Suction pressures are a direct correlation to the ambient temp of the air to the evaporator and RPM of the compressor as well. A 28 to 45 PSI suction pressure reading is a typical pressure swing, based on the heat LOAD.

Do you have a refrigerant sight glass on top of the filter dryer (next to the radiator)? If it shows bubbles passing when at high idle, fan on high and compressor engaged, that would indicate a low charge. The glass SHOULD be clear.

cubicleman · 07-04-2009, 10:10 AM

I'm having a similar problem with my 2004 just recently. Sometimes the AC works and sometimes it doesn't. I noticed that if I really gun the engine the AC will sometime then kick on a second later. I think it's either a bad/sticky relay or the clutch on the compressor starting to go. Can anyone tell me where to find the relay for the AC? Is there a picture posted somewhere? Thanks

Max · 07-04-2009, 11:10 AM

Quote:

if I really gun the engine the AC will sometime then kick on a second later

That doesn't make a whole lot of sense unless the clutch is slipping, thus heating up and it MAYBE decides to eventually lock / engage instead of positive engagement as it should. I would think that you'd have some associated noise when slipping as well.

If you are handy electrically, find the clutch power lead wire coming right off the compressor and momentarily apply 12+ from the battery to it. You'll be bypassing all circuits and directly closing the clutch. If the A/C then works / cools, it's not a clutch issue, but a control circuit problem (relay, thermostat, low / high pressure switch, etc).

cubicleman · 07-04-2009, 01:01 PM

No associated noise. Will see if I give the electrical test a try this weekend. Thx

cubicleman · 07-21-2009, 10:56 PM

I haven't been able to get the problem to repeat itself...the a/c has been working for weeks now...so, no point in trying to jump 12V to the compressor clutch to check it. I'm kind of thinking it was a Relay sticking. I haven't heard of it in quite a few years and when I did it wasn't on use with cars, but I remember years ago where some relays would fail in sticking state and sometime 'unstick'. Assuming there is an A/C relay on the XL-7, I just might see if I pick up a spare and leave it in the glove compartment.

Max · 07-23-2009, 06:07 AM

I'm adding some actual A/C system freon pressures and temps to this thread from another of mine, aimed at ngrome at least. This should help in your troubleshooting toward the correct running parameters.

http://www.suzuki-forums.com/1g-1999...ork-issue.html

ngrome. My gut says that you are now a little overcharged, but you need to observe both the low and HIGH side pressures to confirm.

ngrome · 07-23-2009, 09:05 AM

Quote:

Originally Posted by Max

I'm adding some actual A/C system freon pressures and temps to this thread from another of mine, aimed at ngrome at least. This should help in your troubleshooting toward the correct running parameters.

http://www.suzuki-forums.com/1g-1999...ork-issue.html

ngrome. My gut says that you are now a little overcharged, but you need to observe both the low and HIGH side pressures to confirm.

Thanks, Max. I was thinking that myself, that my AC may be a little overcharged. But I came back from my 2400 mile round trip to and from Chicago a couple weeks ago, and it was weird, but thankfully the AC held up throughout the whole trip. It seemed it kicked in more often and was colder while I was driving on the highway, and don't know if it was because of change of climate and/or region, considering you would think it was cooler and less humid up north. Also, coming out of the vents was sort of that light mist or smoke (though it's not smoke), but you can actually see the cold air blowing out every once in a while. It hasn't done that in a while, as it used to do that in the first couple years we owned the vehicle. Again, I'm thinking because there was less humidity? Like I said, I don't know if I'm imagining things, but it seemed like something got unstuck during the roadtrip to Chicago in the summer (recall my original post it seemed something went wrong during my roadtrip back up to Chicago in the winter), like the AC clutch, because the compressor was noticeably kicking in throughout the trip this time. Kinda weird, but happy that my XL7 is holding up and got 134K miles now, mostly highway (knock on wood).