Re: 98 GC AC Malfunctioning
 

BEK wrote:
> We have a 98 GC 5.9 Lmtd. with 65,000 miles on it. We use the Climate
> Control, setting the temp at 72, and rarely changing it, summer or winter.
> This year since the weather has warmed up and we're needing cooling, the
> system is only working correctly intermittantly. I would say about 30 - 40
> percent of the time it is cooling appropriately. The rest of the time it
> either blows air approximating the outdoor temp or sometimes even heated hot
> air.
>
> If I turn the climate control knob off and then back to auto several times,
> I can usually get it to blow cold air again.
>
> My sister who also has a 98 GC (80,000 miles) is having the same problem and
> so far the mechanics have recharged her freon and replaced the compressor
> and she's still having the problem.
>
> I would love to avoid getting all these expensive repairs done unnecessarily
> and am hoping that somebody here has experienced this as well and can point
> to a solution that isn't so "hit and miss" as my sister has experienced.
>
> Thanks for any help you can give!

It might be worth while pulling any diag codes from the system that
might quickly point out busted components.

For a simple test, turn the thing all the way down to the coldest temp
and then open the doors and run it for about 10 minutes. You should
be getting somewhere near 40 degrees at the vent next to the controls.

Problems with the auto A/C can range from simple loss of charge to
simple stuff like the internal temp sensor [or the fan that drives it]
being messed up.

...and can cost as much to fix as an engine repair.

Re: 98 GC AC Malfunctioning
 

BEK wrote:
> We have a 98 GC 5.9 Lmtd. with 65,000 miles on it. We use the Climate
> Control, setting the temp at 72, and rarely changing it, summer or winter.
> This year since the weather has warmed up and we're needing cooling, the
> system is only working correctly intermittantly. I would say about 30 - 40
> percent of the time it is cooling appropriately. The rest of the time it
> either blows air approximating the outdoor temp or sometimes even heated hot
> air.
>
> If I turn the climate control knob off and then back to auto several times,
> I can usually get it to blow cold air again.
>
> My sister who also has a 98 GC (80,000 miles) is having the same problem and
> so far the mechanics have recharged her freon and replaced the compressor
> and she's still having the problem.
>
> I would love to avoid getting all these expensive repairs done unnecessarily
> and am hoping that somebody here has experienced this as well and can point
> to a solution that isn't so "hit and miss" as my sister has experienced.
>
> Thanks for any help you can give!

It might be worth while pulling any diag codes from the system that
might quickly point out busted components.

For a simple test, turn the thing all the way down to the coldest temp
and then open the doors and run it for about 10 minutes. You should
be getting somewhere near 40 degrees at the vent next to the controls.

Problems with the auto A/C can range from simple loss of charge to
simple stuff like the internal temp sensor [or the fan that drives it]
being messed up.

...and can cost as much to fix as an engine repair.

Re: 98 GC AC Malfunctioning
 

BEK wrote:
> We have a 98 GC 5.9 Lmtd. with 65,000 miles on it. We use the Climate
> Control, setting the temp at 72, and rarely changing it, summer or winter.
> This year since the weather has warmed up and we're needing cooling, the
> system is only working correctly intermittantly. I would say about 30 - 40
> percent of the time it is cooling appropriately. The rest of the time it
> either blows air approximating the outdoor temp or sometimes even heated hot
> air.
>
> If I turn the climate control knob off and then back to auto several times,
> I can usually get it to blow cold air again.
>
> My sister who also has a 98 GC (80,000 miles) is having the same problem and
> so far the mechanics have recharged her freon and replaced the compressor
> and she's still having the problem.
>
> I would love to avoid getting all these expensive repairs done unnecessarily
> and am hoping that somebody here has experienced this as well and can point
> to a solution that isn't so "hit and miss" as my sister has experienced.
>
> Thanks for any help you can give!

It might be worth while pulling any diag codes from the system that
might quickly point out busted components.

For a simple test, turn the thing all the way down to the coldest temp
and then open the doors and run it for about 10 minutes. You should
be getting somewhere near 40 degrees at the vent next to the controls.

Problems with the auto A/C can range from simple loss of charge to
simple stuff like the internal temp sensor [or the fan that drives it]
being messed up.

...and can cost as much to fix as an engine repair.

Re: 98 GC AC Malfunctioning
 

HarryS wrote:


>
> Well, you said the key word you turned it off and then back on and it cools.
> If it was a low charge or a compressor issue it would not cool. It is in
> you climate control switching and associated sensor and damper control. It
> is usually caused by a diaphragm failure of the air box. Which is located in
> your dash behind everything. Allow some times the switch gets dirt on the
> contacts and needs to be removed and cleaned with a good contact cleaner.
> You need to purchase a vacuum hand pump to test the diaphragms. Make sure
> the hoses are tight and draw about 5hg if the needle drops the diaphragm is
> bad replace it also, there usually 1 or more under the dash test them all.
> It is not a hard job just time consuming usually an 8 hour labor charge at
> the local dealer hence the high cost.
>

I don't believe there is a single diaphram in the GC air conditioning
system. It uses servo motors driven by the auto temp control system.

The evaporator is prone to leakage, as is one of the A/C lines that
passes just in front of the battery mount.

With the thing on full chill, fan on high, doors open, if the clutch
cycles frequently at 70-80 degrees ambient, most likely cause is low
charge.

To check the controls, use the Temp rotary and the A/C and Recirc
buttons. [caution, from a 95 Factory Manual...]

Push [ A/C ] and [ RECIRC ] and hold while rotating the temp dial
clockwise one click. All segments should light up.

Let go of the buttons and you should see "00".

Read Diags by pushing EITHER the [A/C] or [RECIRC] but not both.

You should see a stick figure at this point. If the display
stays at "00" there are no fault codes.

If you see 25 or 29, the Auto Temp Control Module is tweaked.

If you see numbers, record them all and in the sequence they appear
and post them for someone with a 98 FSM to decode for you.

Re: 98 GC AC Malfunctioning
 

HarryS wrote:


>
> Well, you said the key word you turned it off and then back on and it cools.
> If it was a low charge or a compressor issue it would not cool. It is in
> you climate control switching and associated sensor and damper control. It
> is usually caused by a diaphragm failure of the air box. Which is located in
> your dash behind everything. Allow some times the switch gets dirt on the
> contacts and needs to be removed and cleaned with a good contact cleaner.
> You need to purchase a vacuum hand pump to test the diaphragms. Make sure
> the hoses are tight and draw about 5hg if the needle drops the diaphragm is
> bad replace it also, there usually 1 or more under the dash test them all.
> It is not a hard job just time consuming usually an 8 hour labor charge at
> the local dealer hence the high cost.
>

I don't believe there is a single diaphram in the GC air conditioning
system. It uses servo motors driven by the auto temp control system.

The evaporator is prone to leakage, as is one of the A/C lines that
passes just in front of the battery mount.

With the thing on full chill, fan on high, doors open, if the clutch
cycles frequently at 70-80 degrees ambient, most likely cause is low
charge.

To check the controls, use the Temp rotary and the A/C and Recirc
buttons. [caution, from a 95 Factory Manual...]

Push [ A/C ] and [ RECIRC ] and hold while rotating the temp dial
clockwise one click. All segments should light up.

Let go of the buttons and you should see "00".

Read Diags by pushing EITHER the [A/C] or [RECIRC] but not both.

You should see a stick figure at this point. If the display
stays at "00" there are no fault codes.

If you see 25 or 29, the Auto Temp Control Module is tweaked.

If you see numbers, record them all and in the sequence they appear
and post them for someone with a 98 FSM to decode for you.

Re: 98 GC AC Malfunctioning
 

HarryS wrote:


>
> Well, you said the key word you turned it off and then back on and it cools.
> If it was a low charge or a compressor issue it would not cool. It is in
> you climate control switching and associated sensor and damper control. It
> is usually caused by a diaphragm failure of the air box. Which is located in
> your dash behind everything. Allow some times the switch gets dirt on the
> contacts and needs to be removed and cleaned with a good contact cleaner.
> You need to purchase a vacuum hand pump to test the diaphragms. Make sure
> the hoses are tight and draw about 5hg if the needle drops the diaphragm is
> bad replace it also, there usually 1 or more under the dash test them all.
> It is not a hard job just time consuming usually an 8 hour labor charge at
> the local dealer hence the high cost.
>

I don't believe there is a single diaphram in the GC air conditioning
system. It uses servo motors driven by the auto temp control system.

The evaporator is prone to leakage, as is one of the A/C lines that
passes just in front of the battery mount.

With the thing on full chill, fan on high, doors open, if the clutch
cycles frequently at 70-80 degrees ambient, most likely cause is low
charge.

To check the controls, use the Temp rotary and the A/C and Recirc
buttons. [caution, from a 95 Factory Manual...]

Push [ A/C ] and [ RECIRC ] and hold while rotating the temp dial
clockwise one click. All segments should light up.

Let go of the buttons and you should see "00".

Read Diags by pushing EITHER the [A/C] or [RECIRC] but not both.

You should see a stick figure at this point. If the display
stays at "00" there are no fault codes.

If you see 25 or 29, the Auto Temp Control Module is tweaked.

If you see numbers, record them all and in the sequence they appear
and post them for someone with a 98 FSM to decode for you.

Re: 98 GC AC Malfunctioning
 

HarryS wrote:


>
> Well, you said the key word you turned it off and then back on and it cools.
> If it was a low charge or a compressor issue it would not cool. It is in
> you climate control switching and associated sensor and damper control. It
> is usually caused by a diaphragm failure of the air box. Which is located in
> your dash behind everything. Allow some times the switch gets dirt on the
> contacts and needs to be removed and cleaned with a good contact cleaner.
> You need to purchase a vacuum hand pump to test the diaphragms. Make sure
> the hoses are tight and draw about 5hg if the needle drops the diaphragm is
> bad replace it also, there usually 1 or more under the dash test them all.
> It is not a hard job just time consuming usually an 8 hour labor charge at
> the local dealer hence the high cost.
>

I don't believe there is a single diaphram in the GC air conditioning
system. It uses servo motors driven by the auto temp control system.

The evaporator is prone to leakage, as is one of the A/C lines that
passes just in front of the battery mount.

With the thing on full chill, fan on high, doors open, if the clutch
cycles frequently at 70-80 degrees ambient, most likely cause is low
charge.

To check the controls, use the Temp rotary and the A/C and Recirc
buttons. [caution, from a 95 Factory Manual...]

Push [ A/C ] and [ RECIRC ] and hold while rotating the temp dial
clockwise one click. All segments should light up.

Let go of the buttons and you should see "00".

Read Diags by pushing EITHER the [A/C] or [RECIRC] but not both.

You should see a stick figure at this point. If the display
stays at "00" there are no fault codes.

If you see 25 or 29, the Auto Temp Control Module is tweaked.

If you see numbers, record them all and in the sequence they appear
and post them for someone with a 98 FSM to decode for you.

Re: 98 GC AC Malfunctioning
 

"Lon" <lon.stowell@comcast.net> wrote in message
news:jT7Ac.62040$HG.29737@attbi_s53...


> Push [ A/C ] and [ RECIRC ] and hold while rotating the temp dial
> clockwise one click. All segments should light up.
>
> Let go of the buttons and you should see "00".
>
> Read Diags by pushing EITHER the [A/C] or [RECIRC] but not both.
>
> You should see a stick figure at this point. If the display
> stays at "00" there are no fault codes.
>
> If you see 25 or 29, the Auto Temp Control Module is tweaked.


Thanks to everybody for the advice. I did follow instructions to read
Diagnostic Codes and all I get is 00....no numbers. Also, tried running for
10 minutes on lowest cool setting/high fan and the air I'm getting from the
dash vents is cool, not cold, but nowhere even close to 40 degrees.
So, if there are any people here with AC experience, I'd appreciate your
input.

Thanks for all your help!
BEK

Re: 98 GC AC Malfunctioning
 

"Lon" <lon.stowell@comcast.net> wrote in message
news:jT7Ac.62040$HG.29737@attbi_s53...


> Push [ A/C ] and [ RECIRC ] and hold while rotating the temp dial
> clockwise one click. All segments should light up.
>
> Let go of the buttons and you should see "00".
>
> Read Diags by pushing EITHER the [A/C] or [RECIRC] but not both.
>
> You should see a stick figure at this point. If the display
> stays at "00" there are no fault codes.
>
> If you see 25 or 29, the Auto Temp Control Module is tweaked.


Thanks to everybody for the advice. I did follow instructions to read
Diagnostic Codes and all I get is 00....no numbers. Also, tried running for
10 minutes on lowest cool setting/high fan and the air I'm getting from the
dash vents is cool, not cold, but nowhere even close to 40 degrees.
So, if there are any people here with AC experience, I'd appreciate your
input.

Thanks for all your help!
BEK

Re: 98 GC AC Malfunctioning
 

"Lon" <lon.stowell@comcast.net> wrote in message
news:jT7Ac.62040$HG.29737@attbi_s53...


> Push [ A/C ] and [ RECIRC ] and hold while rotating the temp dial
> clockwise one click. All segments should light up.
>
> Let go of the buttons and you should see "00".
>
> Read Diags by pushing EITHER the [A/C] or [RECIRC] but not both.
>
> You should see a stick figure at this point. If the display
> stays at "00" there are no fault codes.
>
> If you see 25 or 29, the Auto Temp Control Module is tweaked.


Thanks to everybody for the advice. I did follow instructions to read
Diagnostic Codes and all I get is 00....no numbers. Also, tried running for
10 minutes on lowest cool setting/high fan and the air I'm getting from the
dash vents is cool, not cold, but nowhere even close to 40 degrees.
So, if there are any people here with AC experience, I'd appreciate your
input.

Thanks for all your help!
BEK