HELP...from the A/C GURU
- Thread starter John84GN
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What have you done so far? What are the high side and low side pressures, along with ambient conditions and discharge air temps? It's hard to help you diagnose a problem without having more information, there are a lot of variables to take into account when working on an A/C system and the more you can tell us, the better we can help you.
I didn't want to post until I knew I got someones attention...so here goes...
I went to get my a/c charged at the beginning of summer (apr-may) and the guy said that it didn't hold vaccuum, and found a leak on the evaporator, and did I want him to change it. I didn't want anyone else but ME taking the firewall apart, so I did it, and also changed my heater core while I was there.
I brought the car back, and he charged it...on the way home, the temp never got below about 55, so when I got home, I checked it out under the hood, and I hear a "hissing sound". I traced it to the a/c hose (the one-piece one that goes from the compressor-to-accumulator, and compressor-to-condenser) it seems that one of the crimp connections was the culprit...and I also PISSED $60 bucks away, b/c now I have to take the hose off to repair it! I figured I didn't need air that bad b/c the job included removing the up-pipe, and header to do it ('84 GN)
Now...fast-forward to sunday, I bit the bullet and got it repaired, and brought it away today to get charged, I went to pick it up, and he told me everything is great, but now the temp won't go below 65...AHHHHHHH!!!!!
I took out a stethescope, and noticed that there was a sound (kinda like a "p-sh...p-sh...p-sh") in the line where the oriface tube is, and said that maybe it got clogged during the installation of the hoses this weekend. He agreed. So he took the refrigerant out, I changed the oriface tube, he put new refigerant in, and now we're down to 60 degrees....AHHHHHHHHHH!!!!
... Also, did I mention that the first time he filled the car up w/ refrigerant today, that that was $60, and then now when I went back I paid another $30 (this time he just charged me for just the refrigerant)...
I can't keep PISSING MY MONEY AWAY!!!!!!
The accumulator is ICE COLD, but the air coming out is only about 60-65 degrees...I'm at a loss, and know nothing about the pressures and such?!?
I went to get my a/c charged at the beginning of summer (apr-may) and the guy said that it didn't hold vaccuum, and found a leak on the evaporator, and did I want him to change it. I didn't want anyone else but ME taking the firewall apart, so I did it, and also changed my heater core while I was there.
I brought the car back, and he charged it...on the way home, the temp never got below about 55, so when I got home, I checked it out under the hood, and I hear a "hissing sound". I traced it to the a/c hose (the one-piece one that goes from the compressor-to-accumulator, and compressor-to-condenser) it seems that one of the crimp connections was the culprit...and I also PISSED $60 bucks away, b/c now I have to take the hose off to repair it! I figured I didn't need air that bad b/c the job included removing the up-pipe, and header to do it ('84 GN)
Now...fast-forward to sunday, I bit the bullet and got it repaired, and brought it away today to get charged, I went to pick it up, and he told me everything is great, but now the temp won't go below 65...AHHHHHHH!!!!!
I took out a stethescope, and noticed that there was a sound (kinda like a "p-sh...p-sh...p-sh") in the line where the oriface tube is, and said that maybe it got clogged during the installation of the hoses this weekend. He agreed. So he took the refrigerant out, I changed the oriface tube, he put new refigerant in, and now we're down to 60 degrees....AHHHHHHHHHH!!!!
... Also, did I mention that the first time he filled the car up w/ refrigerant today, that that was $60, and then now when I went back I paid another $30 (this time he just charged me for just the refrigerant)...I can't keep PISSING MY MONEY AWAY!!!!!!
The accumulator is ICE COLD, but the air coming out is only about 60-65 degrees...I'm at a loss, and know nothing about the pressures and such?!?
- Joined
- Jul 20, 2001
- Messages
- 2,205
Just a thought, is cold air being generated before it enters the passenger compartment, or at any of the other vents? Do you know if the door that controls the air to the heater (air blend door) core is closing properly?, Maybe hot ait from the heater core is blending with the cold A/C air.
BoostMasterK
2 boys now, need more GNs
- Joined
- May 28, 2001
- Messages
- 357
It only takes that air blend valve to be open like 1/8th inch to raise the AC temp from 50 to 60. It's a killer.
Mike [
Mike [
Turbo Brian
What do I type here?
- Joined
- May 24, 2001
- Messages
- 574
I thought that the heater control valve closed off coolant flow to the heater core when an A/C function was selected. Is your heater control valve functional? It might be worth checking out.
Checking the heater blend door and heater control valve is a good idea, I'd start by checking that. (I didn't know the TR's had heater control valves, I have a TTA and I don't have a heater control valve.)
You did the one highly recommended thing that most people overlook when doing A/C service, which is changing the orifice tube. It only takes a tiny bit of crap to plug it up, and then the system won't work well at all. It's always worthwhile to change it when you open the system, because it's cheap and easy to change.
Also, how long was your system disconnected when you were working on the evaporator? Did you cap (tightly) the lines when you were replacing it? If you didn't, you might have saturated the dessicant bags in the accumulator with mosture, but if you capped the lines and only had the system apart a short time it is most likely OK.
Since you're taking it to a shop, how is he charging it? Is he using an electronic charging station, or a bottle and a set of gauges? Just trying to cover all the bases.
Definately check the heater control valve and the blend door before you go spending more money.
You did the one highly recommended thing that most people overlook when doing A/C service, which is changing the orifice tube. It only takes a tiny bit of crap to plug it up, and then the system won't work well at all. It's always worthwhile to change it when you open the system, because it's cheap and easy to change.
Also, how long was your system disconnected when you were working on the evaporator? Did you cap (tightly) the lines when you were replacing it? If you didn't, you might have saturated the dessicant bags in the accumulator with mosture, but if you capped the lines and only had the system apart a short time it is most likely OK.
Since you're taking it to a shop, how is he charging it? Is he using an electronic charging station, or a bottle and a set of gauges? Just trying to cover all the bases.
Definately check the heater control valve and the blend door before you go spending more money.
- Joined
- Jul 20, 2001
- Messages
- 2,205
Gokou:
If the TTA is not equipped with a heater control valve, then what controls the flow of water through the heater core?
good thought on the heater door....yes, the cable connecting the slide on the control unit to the door is broken...but here it comes...I already know that...and even if I hold the door in the correct position, no change.
as far as the air before the vents, I think it's about 40 or so...so I think the system is working.
The guy told me not to worry too much about the temp while idling, and that it would drop when I started moving, but at idle it was like 62, and while I drove home, it went up to 69 at one point...and I know....NONE OF THIS MAKES SENSE....just venting
Gokou...the guy's putting it in w/ cans and guages...4 of them to be exact. Instead of using R-134, I told him I didn't want to take the compressor off to change the oil, so he put a new refrigerant in called "freeze 12"...just to let you know...
Thanks
as far as the air before the vents, I think it's about 40 or so...so I think the system is working.
The guy told me not to worry too much about the temp while idling, and that it would drop when I started moving, but at idle it was like 62, and while I drove home, it went up to 69 at one point...and I know....NONE OF THIS MAKES SENSE....just venting
Gokou...the guy's putting it in w/ cans and guages...4 of them to be exact. Instead of using R-134, I told him I didn't want to take the compressor off to change the oil, so he put a new refrigerant in called "freeze 12"...just to let you know...
Thanks
John: he is completely evacuating the system before adding the refridgerant... right? You said he vacuumed the system and found a leak, so he probably is.
I've never messed around with any of the substitues (my R-12 cars get real bonafide R-12) so I don't know if there is any specific percentage to use (i.e. when you convert an R-12 system to R-134a you use about 80% of the R-12 charge to compensate for 134's increased high-side pressures). Maybe someone who has experience with Freeze-12 can chime in. How much is the guy putting into your system? You don't want to undercharge or overcharge it.
And gofstbuick: nothing controls the flow. The heater core gets full coolant flow all the time. The blend door is the only thing that keeps the hot air out of the passenger compartment. Quite a few cars actually don't have heater control valves... most non-A/C cars (old and new) don't use one, and even my 93 Olds Bravada (with A/C) doesn't use a control valve. All depends on the way the system is designed. Generally, systems that have the air travel through both the heater core and evaporator core at all times use a control valve (else the air would always be hot) but systems which have a seperate air path for the heater don't use a control valve because they just bypass air around the heater core, so there is no real need to stop the flow of coolant.
I've never messed around with any of the substitues (my R-12 cars get real bonafide R-12) so I don't know if there is any specific percentage to use (i.e. when you convert an R-12 system to R-134a you use about 80% of the R-12 charge to compensate for 134's increased high-side pressures). Maybe someone who has experience with Freeze-12 can chime in. How much is the guy putting into your system? You don't want to undercharge or overcharge it.
And gofstbuick: nothing controls the flow. The heater core gets full coolant flow all the time. The blend door is the only thing that keeps the hot air out of the passenger compartment. Quite a few cars actually don't have heater control valves... most non-A/C cars (old and new) don't use one, and even my 93 Olds Bravada (with A/C) doesn't use a control valve. All depends on the way the system is designed. Generally, systems that have the air travel through both the heater core and evaporator core at all times use a control valve (else the air would always be hot) but systems which have a seperate air path for the heater don't use a control valve because they just bypass air around the heater core, so there is no real need to stop the flow of coolant.
GOT IT!!!!...and like most things with these cars...I'm the idiot! 
DOH!!!
remember the heater door thing?!?...well um, remember I said that I knew it was broken...well um...I said that I had it closed all the way...well it seems I had it OPEN ALL THE WAY...DOH!
I have since CLOSED it, and got the temp into the mid to low 40's...MUCH BETTER!!!
Thanks for the combined effort from you fellas...YOU guy's are what keep us "stupid" people in check!
Thanks again,
John
DOH!!!
remember the heater door thing?!?...well um, remember I said that I knew it was broken...well um...I said that I had it closed all the way...well it seems I had it OPEN ALL THE WAY...DOH!
I have since CLOSED it, and got the temp into the mid to low 40's...MUCH BETTER!!!
Thanks for the combined effort from you fellas...YOU guy's are what keep us "stupid" people in check!
Thanks again,
John
I do have one question as to the broken "pivot thingie"...To be more specific, I am talking about the V-shaped black plastic piece that the temp cable attaches to at one end, and the threaded rod for the heater door is on the other.
My problem is the base of the V-shaped plastic piece broke off, and I think the piece is discontinued from GM...
Anyone have this problem, or know where I can get the piece?
Thanks...John
My problem is the base of the V-shaped plastic piece broke off, and I think the piece is discontinued from GM...
Anyone have this problem, or know where I can get the piece?
Thanks...John
Turbo Brian
What do I type here?
- Joined
- May 24, 2001
- Messages
- 574
There is a black plastic piece that snaps into the cowl area to hold the cable in place and a black plastic piece on the opposite end of the cable. If one of these is the piece that you are referring to it is part of the cable assembly.
The complete cable assembly is still available new from GM.
The part # is 10000745. GM retail is $9.74. If you have access to a wholesale price it is about $2 cheaper. I replaced that cable on my car a month ago.
The complete cable assembly is still available new from GM.
The part # is 10000745. GM retail is $9.74. If you have access to a wholesale price it is about $2 cheaper. I replaced that cable on my car a month ago.
