93 GC heater/ AC fan on all the time problem
04-08-2004, 11:15 AM
#11
Guest
Posts: n/a
Re: 93 GC heater/ AC fan on all the time problem
---- <LeadWinger> wrote in message news:<9lq970dc6otacbnp95q9ptc7o1isi449cu@4ax.com>. ..
> Everything seems to be controlled by the PCM module, which is the
> large computer under the hood, bolted to the firewall on the passenger
> side. You should be aware that your vehicle has extensive built-in
> testing capability, especially for the HVAC system. You should really
> run through all the tests to pinpoint where the problem is before you
> start replacing things. It's more than I can give you here. I
> recommend you get your hands on the shop manual. There are 7 pages
> devoted to these tests.
>
I ran some basic diagnostics on the Climate control module and it
checks out ok EXCEPT the module does not get the correct fan feedback
speed and it can not control fan speed (i.e. the fan runs at the same
speed no matter what speed I input in test mode).
In the '93s it does not appear that the main body PCM module controls
the fan. There appears to be a separate fan control module hidden
somewhere under the dash that receives its command from the climate
control module.
W.B.
> Everything seems to be controlled by the PCM module, which is the
> large computer under the hood, bolted to the firewall on the passenger
> side. You should be aware that your vehicle has extensive built-in
> testing capability, especially for the HVAC system. You should really
> run through all the tests to pinpoint where the problem is before you
> start replacing things. It's more than I can give you here. I
> recommend you get your hands on the shop manual. There are 7 pages
> devoted to these tests.
>
I ran some basic diagnostics on the Climate control module and it
checks out ok EXCEPT the module does not get the correct fan feedback
speed and it can not control fan speed (i.e. the fan runs at the same
speed no matter what speed I input in test mode).
In the '93s it does not appear that the main body PCM module controls
the fan. There appears to be a separate fan control module hidden
somewhere under the dash that receives its command from the climate
control module.
W.B.
04-08-2004, 11:15 AM
#12
Guest
Posts: n/a
Re: 93 GC heater/ AC fan on all the time problem
---- <LeadWinger> wrote in message news:<9lq970dc6otacbnp95q9ptc7o1isi449cu@4ax.com>. ..
> Everything seems to be controlled by the PCM module, which is the
> large computer under the hood, bolted to the firewall on the passenger
> side. You should be aware that your vehicle has extensive built-in
> testing capability, especially for the HVAC system. You should really
> run through all the tests to pinpoint where the problem is before you
> start replacing things. It's more than I can give you here. I
> recommend you get your hands on the shop manual. There are 7 pages
> devoted to these tests.
>
I ran some basic diagnostics on the Climate control module and it
checks out ok EXCEPT the module does not get the correct fan feedback
speed and it can not control fan speed (i.e. the fan runs at the same
speed no matter what speed I input in test mode).
In the '93s it does not appear that the main body PCM module controls
the fan. There appears to be a separate fan control module hidden
somewhere under the dash that receives its command from the climate
control module.
W.B.
> Everything seems to be controlled by the PCM module, which is the
> large computer under the hood, bolted to the firewall on the passenger
> side. You should be aware that your vehicle has extensive built-in
> testing capability, especially for the HVAC system. You should really
> run through all the tests to pinpoint where the problem is before you
> start replacing things. It's more than I can give you here. I
> recommend you get your hands on the shop manual. There are 7 pages
> devoted to these tests.
>
I ran some basic diagnostics on the Climate control module and it
checks out ok EXCEPT the module does not get the correct fan feedback
speed and it can not control fan speed (i.e. the fan runs at the same
speed no matter what speed I input in test mode).
In the '93s it does not appear that the main body PCM module controls
the fan. There appears to be a separate fan control module hidden
somewhere under the dash that receives its command from the climate
control module.
W.B.
04-08-2004, 11:15 AM
#13
Guest
Posts: n/a
Re: 93 GC heater/ AC fan on all the time problem
---- <LeadWinger> wrote in message news:<9lq970dc6otacbnp95q9ptc7o1isi449cu@4ax.com>. ..
> Everything seems to be controlled by the PCM module, which is the
> large computer under the hood, bolted to the firewall on the passenger
> side. You should be aware that your vehicle has extensive built-in
> testing capability, especially for the HVAC system. You should really
> run through all the tests to pinpoint where the problem is before you
> start replacing things. It's more than I can give you here. I
> recommend you get your hands on the shop manual. There are 7 pages
> devoted to these tests.
>
I ran some basic diagnostics on the Climate control module and it
checks out ok EXCEPT the module does not get the correct fan feedback
speed and it can not control fan speed (i.e. the fan runs at the same
speed no matter what speed I input in test mode).
In the '93s it does not appear that the main body PCM module controls
the fan. There appears to be a separate fan control module hidden
somewhere under the dash that receives its command from the climate
control module.
W.B.
> Everything seems to be controlled by the PCM module, which is the
> large computer under the hood, bolted to the firewall on the passenger
> side. You should be aware that your vehicle has extensive built-in
> testing capability, especially for the HVAC system. You should really
> run through all the tests to pinpoint where the problem is before you
> start replacing things. It's more than I can give you here. I
> recommend you get your hands on the shop manual. There are 7 pages
> devoted to these tests.
>
I ran some basic diagnostics on the Climate control module and it
checks out ok EXCEPT the module does not get the correct fan feedback
speed and it can not control fan speed (i.e. the fan runs at the same
speed no matter what speed I input in test mode).
In the '93s it does not appear that the main body PCM module controls
the fan. There appears to be a separate fan control module hidden
somewhere under the dash that receives its command from the climate
control module.
W.B.
04-08-2004, 09:31 PM
#14
Guest
Posts: n/a
Re: 93 GC heater/ AC fan on all the time problem
On 8 Apr 2004 08:15:41 -0700, barie@city-net.com (WBarie) wrote:
>---- <LeadWinger> wrote in message news:<9lq970dc6otacbnp95q9ptc7o1isi449cu@4ax.com>. ..
>> Everything seems to be controlled by the PCM module, which is the
>> large computer under the hood, bolted to the firewall on the passenger
>> side. You should be aware that your vehicle has extensive built-in
>> testing capability, especially for the HVAC system. You should really
>> run through all the tests to pinpoint where the problem is before you
>> start replacing things. It's more than I can give you here. I
>> recommend you get your hands on the shop manual. There are 7 pages
>> devoted to these tests.
>>
>
>I ran some basic diagnostics on the Climate control module and it
>checks out ok EXCEPT the module does not get the correct fan feedback
>speed and it can not control fan speed (i.e. the fan runs at the same
>speed no matter what speed I input in test mode).
>
>In the '93s it does not appear that the main body PCM module controls
>the fan. There appears to be a separate fan control module hidden
>somewhere under the dash that receives its command from the climate
>control module.
>
>W.B.
The only thing I see between the Controller and the fan motor is
something called a PWR MOD. The way it is drawn it looks like an
integrated circuit. I think an A/D converter. However, the blower
drive coming out of the controller on C9 shouldn't be calling for the
fan to run when it shouldn't be. I still suspect the controller. It
is subject to failure if you get water in that 60-pin connector.
----
>---- <LeadWinger> wrote in message news:<9lq970dc6otacbnp95q9ptc7o1isi449cu@4ax.com>. ..
>> Everything seems to be controlled by the PCM module, which is the
>> large computer under the hood, bolted to the firewall on the passenger
>> side. You should be aware that your vehicle has extensive built-in
>> testing capability, especially for the HVAC system. You should really
>> run through all the tests to pinpoint where the problem is before you
>> start replacing things. It's more than I can give you here. I
>> recommend you get your hands on the shop manual. There are 7 pages
>> devoted to these tests.
>>
>
>I ran some basic diagnostics on the Climate control module and it
>checks out ok EXCEPT the module does not get the correct fan feedback
>speed and it can not control fan speed (i.e. the fan runs at the same
>speed no matter what speed I input in test mode).
>
>In the '93s it does not appear that the main body PCM module controls
>the fan. There appears to be a separate fan control module hidden
>somewhere under the dash that receives its command from the climate
>control module.
>
>W.B.
The only thing I see between the Controller and the fan motor is
something called a PWR MOD. The way it is drawn it looks like an
integrated circuit. I think an A/D converter. However, the blower
drive coming out of the controller on C9 shouldn't be calling for the
fan to run when it shouldn't be. I still suspect the controller. It
is subject to failure if you get water in that 60-pin connector.
----
04-08-2004, 09:31 PM
#15
Guest
Posts: n/a
Re: 93 GC heater/ AC fan on all the time problem
On 8 Apr 2004 08:15:41 -0700, barie@city-net.com (WBarie) wrote:
>---- <LeadWinger> wrote in message news:<9lq970dc6otacbnp95q9ptc7o1isi449cu@4ax.com>. ..
>> Everything seems to be controlled by the PCM module, which is the
>> large computer under the hood, bolted to the firewall on the passenger
>> side. You should be aware that your vehicle has extensive built-in
>> testing capability, especially for the HVAC system. You should really
>> run through all the tests to pinpoint where the problem is before you
>> start replacing things. It's more than I can give you here. I
>> recommend you get your hands on the shop manual. There are 7 pages
>> devoted to these tests.
>>
>
>I ran some basic diagnostics on the Climate control module and it
>checks out ok EXCEPT the module does not get the correct fan feedback
>speed and it can not control fan speed (i.e. the fan runs at the same
>speed no matter what speed I input in test mode).
>
>In the '93s it does not appear that the main body PCM module controls
>the fan. There appears to be a separate fan control module hidden
>somewhere under the dash that receives its command from the climate
>control module.
>
>W.B.
The only thing I see between the Controller and the fan motor is
something called a PWR MOD. The way it is drawn it looks like an
integrated circuit. I think an A/D converter. However, the blower
drive coming out of the controller on C9 shouldn't be calling for the
fan to run when it shouldn't be. I still suspect the controller. It
is subject to failure if you get water in that 60-pin connector.
----
>---- <LeadWinger> wrote in message news:<9lq970dc6otacbnp95q9ptc7o1isi449cu@4ax.com>. ..
>> Everything seems to be controlled by the PCM module, which is the
>> large computer under the hood, bolted to the firewall on the passenger
>> side. You should be aware that your vehicle has extensive built-in
>> testing capability, especially for the HVAC system. You should really
>> run through all the tests to pinpoint where the problem is before you
>> start replacing things. It's more than I can give you here. I
>> recommend you get your hands on the shop manual. There are 7 pages
>> devoted to these tests.
>>
>
>I ran some basic diagnostics on the Climate control module and it
>checks out ok EXCEPT the module does not get the correct fan feedback
>speed and it can not control fan speed (i.e. the fan runs at the same
>speed no matter what speed I input in test mode).
>
>In the '93s it does not appear that the main body PCM module controls
>the fan. There appears to be a separate fan control module hidden
>somewhere under the dash that receives its command from the climate
>control module.
>
>W.B.
The only thing I see between the Controller and the fan motor is
something called a PWR MOD. The way it is drawn it looks like an
integrated circuit. I think an A/D converter. However, the blower
drive coming out of the controller on C9 shouldn't be calling for the
fan to run when it shouldn't be. I still suspect the controller. It
is subject to failure if you get water in that 60-pin connector.
----
04-08-2004, 09:31 PM
#16
Guest
Posts: n/a
Re: 93 GC heater/ AC fan on all the time problem
On 8 Apr 2004 08:15:41 -0700, barie@city-net.com (WBarie) wrote:
>---- <LeadWinger> wrote in message news:<9lq970dc6otacbnp95q9ptc7o1isi449cu@4ax.com>. ..
>> Everything seems to be controlled by the PCM module, which is the
>> large computer under the hood, bolted to the firewall on the passenger
>> side. You should be aware that your vehicle has extensive built-in
>> testing capability, especially for the HVAC system. You should really
>> run through all the tests to pinpoint where the problem is before you
>> start replacing things. It's more than I can give you here. I
>> recommend you get your hands on the shop manual. There are 7 pages
>> devoted to these tests.
>>
>
>I ran some basic diagnostics on the Climate control module and it
>checks out ok EXCEPT the module does not get the correct fan feedback
>speed and it can not control fan speed (i.e. the fan runs at the same
>speed no matter what speed I input in test mode).
>
>In the '93s it does not appear that the main body PCM module controls
>the fan. There appears to be a separate fan control module hidden
>somewhere under the dash that receives its command from the climate
>control module.
>
>W.B.
The only thing I see between the Controller and the fan motor is
something called a PWR MOD. The way it is drawn it looks like an
integrated circuit. I think an A/D converter. However, the blower
drive coming out of the controller on C9 shouldn't be calling for the
fan to run when it shouldn't be. I still suspect the controller. It
is subject to failure if you get water in that 60-pin connector.
----
>---- <LeadWinger> wrote in message news:<9lq970dc6otacbnp95q9ptc7o1isi449cu@4ax.com>. ..
>> Everything seems to be controlled by the PCM module, which is the
>> large computer under the hood, bolted to the firewall on the passenger
>> side. You should be aware that your vehicle has extensive built-in
>> testing capability, especially for the HVAC system. You should really
>> run through all the tests to pinpoint where the problem is before you
>> start replacing things. It's more than I can give you here. I
>> recommend you get your hands on the shop manual. There are 7 pages
>> devoted to these tests.
>>
>
>I ran some basic diagnostics on the Climate control module and it
>checks out ok EXCEPT the module does not get the correct fan feedback
>speed and it can not control fan speed (i.e. the fan runs at the same
>speed no matter what speed I input in test mode).
>
>In the '93s it does not appear that the main body PCM module controls
>the fan. There appears to be a separate fan control module hidden
>somewhere under the dash that receives its command from the climate
>control module.
>
>W.B.
The only thing I see between the Controller and the fan motor is
something called a PWR MOD. The way it is drawn it looks like an
integrated circuit. I think an A/D converter. However, the blower
drive coming out of the controller on C9 shouldn't be calling for the
fan to run when it shouldn't be. I still suspect the controller. It
is subject to failure if you get water in that 60-pin connector.
----
04-08-2004, 09:31 PM
#17
Guest
Posts: n/a
Re: 93 GC heater/ AC fan on all the time problem
On 8 Apr 2004 08:15:41 -0700, barie@city-net.com (WBarie) wrote:
>---- <LeadWinger> wrote in message news:<9lq970dc6otacbnp95q9ptc7o1isi449cu@4ax.com>. ..
>> Everything seems to be controlled by the PCM module, which is the
>> large computer under the hood, bolted to the firewall on the passenger
>> side. You should be aware that your vehicle has extensive built-in
>> testing capability, especially for the HVAC system. You should really
>> run through all the tests to pinpoint where the problem is before you
>> start replacing things. It's more than I can give you here. I
>> recommend you get your hands on the shop manual. There are 7 pages
>> devoted to these tests.
>>
>
>I ran some basic diagnostics on the Climate control module and it
>checks out ok EXCEPT the module does not get the correct fan feedback
>speed and it can not control fan speed (i.e. the fan runs at the same
>speed no matter what speed I input in test mode).
>
>In the '93s it does not appear that the main body PCM module controls
>the fan. There appears to be a separate fan control module hidden
>somewhere under the dash that receives its command from the climate
>control module.
>
>W.B.
The only thing I see between the Controller and the fan motor is
something called a PWR MOD. The way it is drawn it looks like an
integrated circuit. I think an A/D converter. However, the blower
drive coming out of the controller on C9 shouldn't be calling for the
fan to run when it shouldn't be. I still suspect the controller. It
is subject to failure if you get water in that 60-pin connector.
----
>---- <LeadWinger> wrote in message news:<9lq970dc6otacbnp95q9ptc7o1isi449cu@4ax.com>. ..
>> Everything seems to be controlled by the PCM module, which is the
>> large computer under the hood, bolted to the firewall on the passenger
>> side. You should be aware that your vehicle has extensive built-in
>> testing capability, especially for the HVAC system. You should really
>> run through all the tests to pinpoint where the problem is before you
>> start replacing things. It's more than I can give you here. I
>> recommend you get your hands on the shop manual. There are 7 pages
>> devoted to these tests.
>>
>
>I ran some basic diagnostics on the Climate control module and it
>checks out ok EXCEPT the module does not get the correct fan feedback
>speed and it can not control fan speed (i.e. the fan runs at the same
>speed no matter what speed I input in test mode).
>
>In the '93s it does not appear that the main body PCM module controls
>the fan. There appears to be a separate fan control module hidden
>somewhere under the dash that receives its command from the climate
>control module.
>
>W.B.
The only thing I see between the Controller and the fan motor is
something called a PWR MOD. The way it is drawn it looks like an
integrated circuit. I think an A/D converter. However, the blower
drive coming out of the controller on C9 shouldn't be calling for the
fan to run when it shouldn't be. I still suspect the controller. It
is subject to failure if you get water in that 60-pin connector.
----
04-08-2004, 09:54 PM
#18
Guest
Posts: n/a
Re: 93 GC heater/ AC fan on all the time problem
---- did pass the time by typing:
> The only thing I see between the Controller and the fan motor is
> something called a PWR MOD. The way it is drawn it looks like an
> integrated circuit. I think an A/D converter. However, the blower
> drive coming out of the controller on C9 shouldn't be calling for the
> fan to run when it shouldn't be. I still suspect the controller. It
> is subject to failure if you get water in that 60-pin connector.
The PWR mod takes a signal on the Brown(yellow stripe) wire from the
HEVAC controller, Pin 9. It's basically an SCR or power switching
module.
Have you checked the blower-high relay to see that it isn't stuck?
Don't exactly remember where that realay is. Think it was down by the
module wrapped up in tape. It's been a while and my ZJ doesn't have
the automagic climate stuff.
--
DougW
> The only thing I see between the Controller and the fan motor is
> something called a PWR MOD. The way it is drawn it looks like an
> integrated circuit. I think an A/D converter. However, the blower
> drive coming out of the controller on C9 shouldn't be calling for the
> fan to run when it shouldn't be. I still suspect the controller. It
> is subject to failure if you get water in that 60-pin connector.
The PWR mod takes a signal on the Brown(yellow stripe) wire from the
HEVAC controller, Pin 9. It's basically an SCR or power switching
module.
Have you checked the blower-high relay to see that it isn't stuck?
Don't exactly remember where that realay is. Think it was down by the
module wrapped up in tape. It's been a while and my ZJ doesn't have
the automagic climate stuff.
--
DougW
04-08-2004, 09:54 PM
#19
Guest
Posts: n/a
Re: 93 GC heater/ AC fan on all the time problem
---- did pass the time by typing:
> The only thing I see between the Controller and the fan motor is
> something called a PWR MOD. The way it is drawn it looks like an
> integrated circuit. I think an A/D converter. However, the blower
> drive coming out of the controller on C9 shouldn't be calling for the
> fan to run when it shouldn't be. I still suspect the controller. It
> is subject to failure if you get water in that 60-pin connector.
The PWR mod takes a signal on the Brown(yellow stripe) wire from the
HEVAC controller, Pin 9. It's basically an SCR or power switching
module.
Have you checked the blower-high relay to see that it isn't stuck?
Don't exactly remember where that realay is. Think it was down by the
module wrapped up in tape. It's been a while and my ZJ doesn't have
the automagic climate stuff.
--
DougW
> The only thing I see between the Controller and the fan motor is
> something called a PWR MOD. The way it is drawn it looks like an
> integrated circuit. I think an A/D converter. However, the blower
> drive coming out of the controller on C9 shouldn't be calling for the
> fan to run when it shouldn't be. I still suspect the controller. It
> is subject to failure if you get water in that 60-pin connector.
The PWR mod takes a signal on the Brown(yellow stripe) wire from the
HEVAC controller, Pin 9. It's basically an SCR or power switching
module.
Have you checked the blower-high relay to see that it isn't stuck?
Don't exactly remember where that realay is. Think it was down by the
module wrapped up in tape. It's been a while and my ZJ doesn't have
the automagic climate stuff.
--
DougW
04-08-2004, 09:54 PM
#20
Guest
Posts: n/a
Re: 93 GC heater/ AC fan on all the time problem
---- did pass the time by typing:
> The only thing I see between the Controller and the fan motor is
> something called a PWR MOD. The way it is drawn it looks like an
> integrated circuit. I think an A/D converter. However, the blower
> drive coming out of the controller on C9 shouldn't be calling for the
> fan to run when it shouldn't be. I still suspect the controller. It
> is subject to failure if you get water in that 60-pin connector.
The PWR mod takes a signal on the Brown(yellow stripe) wire from the
HEVAC controller, Pin 9. It's basically an SCR or power switching
module.
Have you checked the blower-high relay to see that it isn't stuck?
Don't exactly remember where that realay is. Think it was down by the
module wrapped up in tape. It's been a while and my ZJ doesn't have
the automagic climate stuff.
--
DougW
> The only thing I see between the Controller and the fan motor is
> something called a PWR MOD. The way it is drawn it looks like an
> integrated circuit. I think an A/D converter. However, the blower
> drive coming out of the controller on C9 shouldn't be calling for the
> fan to run when it shouldn't be. I still suspect the controller. It
> is subject to failure if you get water in that 60-pin connector.
The PWR mod takes a signal on the Brown(yellow stripe) wire from the
HEVAC controller, Pin 9. It's basically an SCR or power switching
module.
Have you checked the blower-high relay to see that it isn't stuck?
Don't exactly remember where that realay is. Think it was down by the
module wrapped up in tape. It's been a while and my ZJ doesn't have
the automagic climate stuff.
--
DougW