99 Sierra AC Issue: It's getting hot down here... - Page 2 - GM Forum - Buick, Cadillac, Chev, Olds, GMC & Pontiac chat


GMC/Chevrolet Truck/SUV When starting new posts, please specify YEAR, MAKE, MODEL, ENGINE type, and whatever modifications you have made.

Reply
 
 
 
Thread Tools Search this Thread
Old 04-12-2012, 05:50 PM   #11
Junior Member
Posts like a Ricer Type-R
Thread Starter
 
Join Date: Apr 2012
Posts: 10
Thanks: 0
Thanked 0 Times in 0 Posts
tulse is on a distinguished road
Default

Quote:
Originally Posted by jwfirebird View Post
next i would back probe the plug for the clutch and see if its getting power while it malfunctioning or if something is shutting it down

Will do that first thing tomorrow. Looks like fun getting to it.

I'll will post up what I find.

Thanks again. This is very helpful.
tulse is offline   Reply With Quote
Old 04-12-2012, 06:14 PM   #12
Senior Member
True Car Nut
 
jwfirebird's Avatar
 
Join Date: Dec 2009
Location: western,ny state
Posts: 9,616
Thanked 563 Times in 481 Posts
jwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond repute
Default

i probably wont be able to check in tomorrow but i hope you find it.
jwfirebird is offline   Reply With Quote
Old 04-15-2012, 08:26 PM   #13
Junior Member
Posts like a V-Tak
 
Join Date: Mar 2012
Location: west of chicago, il
Posts: 26
Thanks: 0
Thanked 0 Times in 0 Posts
greg409 is on a distinguished road
Default

If the compressor restarts after sitting (engine idling), my money'* on a borderline low charge.

When you're driving, the condenser press/temp drops, tripping the low press switch.

I agree with JWfirebird, check the voltage to the a/c clutch when it stops, I bet you'll find 0 volts.

When the **** is on "MAX", you're running recirc air, causing the pressures to drop even more (it'* cooler in your truck than outside)

luck,greg
greg409 is offline   Reply With Quote
Old 04-15-2012, 08:29 PM   #14
Junior Member
Posts like a V-Tak
 
Join Date: Mar 2012
Location: west of chicago, il
Posts: 26
Thanks: 0
Thanked 0 Times in 0 Posts
greg409 is on a distinguished road
Default

I can't edit yet

You might pull the plug while the compresser has failed, check both terms to ground.


luck,greg
greg409 is offline   Reply With Quote
Old 04-15-2012, 08:52 PM   #15
Junior Member
Posts like a Ricer Type-R
Thread Starter
 
Join Date: Apr 2012
Posts: 10
Thanks: 0
Thanked 0 Times in 0 Posts
tulse is on a distinguished road
Default

Damn. I saw this all after I messed with it today. I had the passenger front wheel off and the switch was pretty easy to get to through the wheel well.

I could not get the A/C to stop blowing cold. Now I know why. I was working on the brakes while I was letting the A/C blow.... With the windows down. Whoops.

When I check the switch it had 12, of course.

So, should I just put a little charge in it and see what happens. I have some coolant.
tulse is offline   Reply With Quote
Old 04-15-2012, 09:06 PM   #16
Junior Member
Posts like a V-Tak
 
Join Date: Mar 2012
Location: west of chicago, il
Posts: 26
Thanks: 0
Thanked 0 Times in 0 Posts
greg409 is on a distinguished road
Default

Back in the early 70'* I was a Mercedes tech, when we did a/c, we had a large 24" fan in front of the rad (simulating 30mph), all windows down, a/c blower on med.
just fyi

My sonoma wasn't working, I did a similiar setup, put in a half a can and when the a/c clutch pulled in, I shot the rest of the can in. (upright & shakin')

It blew the valves in the compressor, so I'd only put in enough to bring on the compressor and stop.

If that doesn't resolve it, read more or take it in to a shop, I don't know the test pressures for your truck (if you're using numerical gauges)

luck,greg
greg409 is offline   Reply With Quote
Old 04-15-2012, 10:00 PM   #17
Junior Member
Posts like a Ricer Type-R
Thread Starter
 
Join Date: Apr 2012
Posts: 10
Thanks: 0
Thanked 0 Times in 0 Posts
tulse is on a distinguished road
Default

Thanks a lot for the input guys.

I just put the gauges back on.

43 on the low
190 high

How high should I take the pressure on the low?
tulse is offline   Reply With Quote
Old 04-15-2012, 10:02 PM   #18
Junior Member
Posts like a Ricer Type-R
Thread Starter
 
Join Date: Apr 2012
Posts: 10
Thanks: 0
Thanked 0 Times in 0 Posts
tulse is on a distinguished road
Default

Sorry, can't edit either.

I'll try to look for a service manual to check low side pressure numbers.
tulse is offline   Reply With Quote
Old 04-16-2012, 12:39 AM   #19
Junior Member
Posts like a V-Tak
 
Join Date: Mar 2012
Location: west of chicago, il
Posts: 26
Thanks: 0
Thanked 0 Times in 0 Posts
greg409 is on a distinguished road
Default

If you were running on "MAX" (recirculated air) for long enough to de-humidify & cool down the interior AND had a fan blowing air across the condensor (assuming 75ish outside temp) - I'd leave it there.

The low (suction) pressure is close to the evap coil press (inside the truck)
The air across the coil will run 10deg warmer than the press (in general)
That should put you @ about 55ish disch air temp out of vents
Understand the press & temp is going to drop as the interior cools down, that'* why we don't test on "max" - since the readings will change.

But I think the 43 suction as bad, if there'* a decent load on it.
The 190 high is dependent on airflow & air temp across the cond coil (and cleanliness of coil)

luck,greg
greg409 is offline   Reply With Quote
Old 04-16-2012, 12:42 AM   #20
Junior Member
Posts like a V-Tak
 
Join Date: Mar 2012
Location: west of chicago, il
Posts: 26
Thanks: 0
Thanked 0 Times in 0 Posts
greg409 is on a distinguished road
Default

I hate this no-edit

I meant to say the 43# suction is NOT bad, if there'* a load on it

Depends on load, blower speed, etc.

luck,greg
greg409 is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
99 aurora 4.0 Engine getting Hot Issue ljwatson Oldsmobile 2 02-15-2014 03:55 PM
hot hot hot jhill52788 1992-1999 2 07-07-2007 06:18 PM
HOT HOT HOT! BonneMeMN Lounge 22 06-25-2005 12:46 AM
Feelin Hot Hot Hot LittleHoov General GM Chat 10 08-07-2003 01:41 PM


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -4. The time now is 06:56 AM.


We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.