Jump to content

2001 Suburban AC intermittent


Recommended Posts

2001 1500LS, 140k

 

Problem started last year and may be getting worse. At random times (idle or while driving) the AC will cut off. Fan stays running but it gets hot and humid. Whenever it decides, it will turn back on. I've tried changing all of the settings and I can't make it come back on until it's ready. Sometimes it's 30 seconds, sometimes minutes. When it works, which is most of the time, it cools just fine. Of course it won't do this in the driveway so I can't check for the compressor running, pressures, etc.

Link to comment
Share on other sites

Keep a gauge in your truck and the next time it happens pull into a gas station and check the pressure. My guess is that you'll find it's too high, indicating a blockage in your system somewhere. Your pressure switch is cutting out the compressor, and after a period of inactivity it "bleeds down" back into normal range.

Link to comment
Share on other sites

Sounds like an intermittent connection issue to me. Next time it stops working, try tugging on the connector that goes down to the compressor, and / or pull the AC control unit out and pull on that harness. And make sure the A/C relay isn't bent or anything.

 

PS..don't be discouraged by the jackasses here. They know absolutely everything, obviously, but are too good to share their info.

Link to comment
Share on other sites

Thanks 06SierraZ71, and the others that have provided helpful comments.

 

I laughed at the one not so helpful one. The one who has no idea my background or capabilities, or the places and help I can provide where I know more than full-size Chevy trucks and the fine details of AC systems with subtle problems. I've been on the net longer than most (once upon a time it was BITnet) and don't dwell on things like that.

 

I also work best by the medical school philosophy of learning - "read one, see one, do one." Well, at least one of the first two. I am impressed by my friends that have the gift of tearing into something with no idea what they are doing. Not my style. I like to be at least a little prepared. It leads to less jobs that need to be stopped mid-course to go get a part or figure out how to do something. I wish I had more garage time where I could putter and tackle things like that. I need to be more efficient with my time, and especially the Suburban which almost fits in the garage. If I start a project and it's down for a week in the middle, it will be a serious inconvenience.

 

I asked for two clarifications. I've replaced a compressor (and other parts, done R134a conversions, have a pump and gauges so this isn't totally new to me) but never disassembled one, and was sitting in a hotel room without access to the shop manual or the vehicle to look at. The other talked about a pressure switch and being too high in pressure. I assumed it was low side, but I figured it was safer to ask. Apparently one person didn't think I should ask and I should pretend like I know everything. Oh well. Won't keep me from asking again.

 

To get back on topic, the problem is very intermittent. Over the past two years or so, once a week to once every 2-3 months the system will stop sending cold air into the truck for 30-250 seconds at a time. All other times it works perfect and blows nice and cold on all fan speeds with good balanced temps throughout.

 

I'll get myself prepared to troubleshoot if I can catch it in the act.

Link to comment
Share on other sites

Unfortunately I am not knowledgeable enough to help much more than check all the usuals, fuses, wires, switches, pressures, etc. As it is such an infrequent occurance of a problem it will be difficult to diagnose and repair. The only thing I have to add is please make sure you don't get frustrated and start throwing parts at it "hoping" it will fix it. If you find a possible problem please make sure it is "the" problem. In my work, it's not too different, people continue to fix "symptoms" and don't even consider the "problem" when troubleshooting.

Link to comment
Share on other sites

06, I wasn't referring to your post! Just the couple people on this forum that tend to troll and never post any valuable info.

 

Like I said in my earlier post, check the electrical connections. It doesn't sound mechanical IMO, unless you're low on r134. My truck does the exact same thing, and the issue is a poor connection in the harness going to the compressor. When it doesn't work, I can open the hood, tug on that harness, and the compressor will immediately engage. Not saying that's your issue, but I bet it's electrical.

Link to comment
Share on other sites

06, I wasn't referring to your post! Just the couple people on this forum that tend to troll and never post any valuable info.

 

Like I said in my earlier post, check the electrical connections. It doesn't sound mechanical IMO, unless you're low on r134. My truck does the exact same thing, and the issue is a poor connection in the harness going to the compressor. When it doesn't work, I can open the hood, tug on that harness, and the compressor will immediately engage. Not saying that's your issue, but I bet it's electrical.

 

:cheers:

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

  • Recently Browsing   0 members

    • No registered users viewing this page.
  • Forum Statistics

    246.7k
    Total Topics
    2.6m
    Total Posts
  • Member Statistics

    334,633
    Total Members
    8,960
    Most Online
    Rickj420
    Newest Member
    Rickj420
    Joined
  • Who's Online   1 Member, 0 Anonymous, 384 Guests (See full list)



×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use.