93 GC heater/ AC fan on all the time problem
04-07-2004, 10:18 PM
#1
Guest
Posts: n/a
93 GC heater/ AC fan on all the time problem
Well, my heater / AC fan is now staying on all the time even with the
key off. If I turn the control to HI I hear the high speed relay click
and the fan actually goes a little bit faster so I don't think that it
is a high speed fan relay problem. Searching the archives this appears
to be the sign of a bad fan control module.
My question is where is the fan control module located? Do I need to
remove the glove compartment, pass side dash board, or can I get to it
from underneath (or is it somewhere else completely?). Also can anyone
describe it so that I know what I am looking for. Oh and my GC has the
automatic climate control system.
Any help would be appreciated.
Walt B.
key off. If I turn the control to HI I hear the high speed relay click
and the fan actually goes a little bit faster so I don't think that it
is a high speed fan relay problem. Searching the archives this appears
to be the sign of a bad fan control module.
My question is where is the fan control module located? Do I need to
remove the glove compartment, pass side dash board, or can I get to it
from underneath (or is it somewhere else completely?). Also can anyone
describe it so that I know what I am looking for. Oh and my GC has the
automatic climate control system.
Any help would be appreciated.
Walt B.
04-08-2004, 02:05 AM
#2
Guest
Posts: n/a
Re: 93 GC heater/ AC fan on all the time problem
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.
----
On Wed, 07 Apr 2004 22:18:53 -0400, Walt Barie <barie@city-net.com>
wrote:
>Well, my heater / AC fan is now staying on all the time even with the
>key off. If I turn the control to HI I hear the high speed relay click
>and the fan actually goes a little bit faster so I don't think that it
>is a high speed fan relay problem. Searching the archives this appears
>to be the sign of a bad fan control module.
>
>My question is where is the fan control module located? Do I need to
>remove the glove compartment, pass side dash board, or can I get to it
>from underneath (or is it somewhere else completely?). Also can anyone
>describe it so that I know what I am looking for. Oh and my GC has the
>automatic climate control system.
>
>Any help would be appreciated.
>
>Walt B.
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.
----
On Wed, 07 Apr 2004 22:18:53 -0400, Walt Barie <barie@city-net.com>
wrote:
>Well, my heater / AC fan is now staying on all the time even with the
>key off. If I turn the control to HI I hear the high speed relay click
>and the fan actually goes a little bit faster so I don't think that it
>is a high speed fan relay problem. Searching the archives this appears
>to be the sign of a bad fan control module.
>
>My question is where is the fan control module located? Do I need to
>remove the glove compartment, pass side dash board, or can I get to it
>from underneath (or is it somewhere else completely?). Also can anyone
>describe it so that I know what I am looking for. Oh and my GC has the
>automatic climate control system.
>
>Any help would be appreciated.
>
>Walt B.
04-08-2004, 02:05 AM
#3
Guest
Posts: n/a
Re: 93 GC heater/ AC fan on all the time problem
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.
----
On Wed, 07 Apr 2004 22:18:53 -0400, Walt Barie <barie@city-net.com>
wrote:
>Well, my heater / AC fan is now staying on all the time even with the
>key off. If I turn the control to HI I hear the high speed relay click
>and the fan actually goes a little bit faster so I don't think that it
>is a high speed fan relay problem. Searching the archives this appears
>to be the sign of a bad fan control module.
>
>My question is where is the fan control module located? Do I need to
>remove the glove compartment, pass side dash board, or can I get to it
>from underneath (or is it somewhere else completely?). Also can anyone
>describe it so that I know what I am looking for. Oh and my GC has the
>automatic climate control system.
>
>Any help would be appreciated.
>
>Walt B.
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.
----
On Wed, 07 Apr 2004 22:18:53 -0400, Walt Barie <barie@city-net.com>
wrote:
>Well, my heater / AC fan is now staying on all the time even with the
>key off. If I turn the control to HI I hear the high speed relay click
>and the fan actually goes a little bit faster so I don't think that it
>is a high speed fan relay problem. Searching the archives this appears
>to be the sign of a bad fan control module.
>
>My question is where is the fan control module located? Do I need to
>remove the glove compartment, pass side dash board, or can I get to it
>from underneath (or is it somewhere else completely?). Also can anyone
>describe it so that I know what I am looking for. Oh and my GC has the
>automatic climate control system.
>
>Any help would be appreciated.
>
>Walt B.
04-08-2004, 02:05 AM
#4
Guest
Posts: n/a
Re: 93 GC heater/ AC fan on all the time problem
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.
----
On Wed, 07 Apr 2004 22:18:53 -0400, Walt Barie <barie@city-net.com>
wrote:
>Well, my heater / AC fan is now staying on all the time even with the
>key off. If I turn the control to HI I hear the high speed relay click
>and the fan actually goes a little bit faster so I don't think that it
>is a high speed fan relay problem. Searching the archives this appears
>to be the sign of a bad fan control module.
>
>My question is where is the fan control module located? Do I need to
>remove the glove compartment, pass side dash board, or can I get to it
>from underneath (or is it somewhere else completely?). Also can anyone
>describe it so that I know what I am looking for. Oh and my GC has the
>automatic climate control system.
>
>Any help would be appreciated.
>
>Walt B.
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.
----
On Wed, 07 Apr 2004 22:18:53 -0400, Walt Barie <barie@city-net.com>
wrote:
>Well, my heater / AC fan is now staying on all the time even with the
>key off. If I turn the control to HI I hear the high speed relay click
>and the fan actually goes a little bit faster so I don't think that it
>is a high speed fan relay problem. Searching the archives this appears
>to be the sign of a bad fan control module.
>
>My question is where is the fan control module located? Do I need to
>remove the glove compartment, pass side dash board, or can I get to it
>from underneath (or is it somewhere else completely?). Also can anyone
>describe it so that I know what I am looking for. Oh and my GC has the
>automatic climate control system.
>
>Any help would be appreciated.
>
>Walt B.
04-08-2004, 02:05 AM
#5
Guest
Posts: n/a
Re: 93 GC heater/ AC fan on all the time problem
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.
----
On Wed, 07 Apr 2004 22:18:53 -0400, Walt Barie <barie@city-net.com>
wrote:
>Well, my heater / AC fan is now staying on all the time even with the
>key off. If I turn the control to HI I hear the high speed relay click
>and the fan actually goes a little bit faster so I don't think that it
>is a high speed fan relay problem. Searching the archives this appears
>to be the sign of a bad fan control module.
>
>My question is where is the fan control module located? Do I need to
>remove the glove compartment, pass side dash board, or can I get to it
>from underneath (or is it somewhere else completely?). Also can anyone
>describe it so that I know what I am looking for. Oh and my GC has the
>automatic climate control system.
>
>Any help would be appreciated.
>
>Walt B.
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.
----
On Wed, 07 Apr 2004 22:18:53 -0400, Walt Barie <barie@city-net.com>
wrote:
>Well, my heater / AC fan is now staying on all the time even with the
>key off. If I turn the control to HI I hear the high speed relay click
>and the fan actually goes a little bit faster so I don't think that it
>is a high speed fan relay problem. Searching the archives this appears
>to be the sign of a bad fan control module.
>
>My question is where is the fan control module located? Do I need to
>remove the glove compartment, pass side dash board, or can I get to it
>from underneath (or is it somewhere else completely?). Also can anyone
>describe it so that I know what I am looking for. Oh and my GC has the
>automatic climate control system.
>
>Any help would be appreciated.
>
>Walt B.
04-08-2004, 07:49 AM
#6
Guest
Posts: n/a
Re: 93 GC heater/ AC fan on all the time problem
Walt Barie did pass the time by typing:
> Well, my heater / AC fan is now staying on all the time even with the
> key off. If I turn the control to HI I hear the high speed relay click
> and the fan actually goes a little bit faster so I don't think that it
> is a high speed fan relay problem. Searching the archives this appears
> to be the sign of a bad fan control module.
>
> My question is where is the fan control module located? Do I need to
> remove the glove compartment, pass side dash board, or can I get to it
> from underneath (or is it somewhere else completely?). Also can anyone
> describe it so that I know what I am looking for. Oh and my GC has the
> automatic climate control system.
>
> Any help would be appreciated.
Yep. More than likely the power module.
You can pull Fuse 11 (30A in the distribution center
behind battery) And that will remove power to the system.
Run the ATC diags.
- Turn the key to ON
- Depress A/C and RECIRC at the same time and turn the
temperature **** one click to the right.
- Keep holding the A/C and RECIRC buttons and all the stick
figure lamps will light up (lamp test)
- Release the buttons.
- Push either A/C or RECIRC once
Record the numbers that display.
00 = none or end of cycle.
There are other tests that can be done from the buttons but
for now just stop the test by turning the key off
I'll scan the pages for you but it will be later today.
Gotta go to work.
--
-- DougW -- 93 ZJ 4.0 http://members.***.net/wilsond
HESCO Supercharger - 300W IASCA Stereo - Edelbrock IAS Shocks
Gibson Exhaust - rear DCpower - custom gauge install - Stillen Rotors
> Well, my heater / AC fan is now staying on all the time even with the
> key off. If I turn the control to HI I hear the high speed relay click
> and the fan actually goes a little bit faster so I don't think that it
> is a high speed fan relay problem. Searching the archives this appears
> to be the sign of a bad fan control module.
>
> My question is where is the fan control module located? Do I need to
> remove the glove compartment, pass side dash board, or can I get to it
> from underneath (or is it somewhere else completely?). Also can anyone
> describe it so that I know what I am looking for. Oh and my GC has the
> automatic climate control system.
>
> Any help would be appreciated.
Yep. More than likely the power module.
You can pull Fuse 11 (30A in the distribution center
behind battery) And that will remove power to the system.
Run the ATC diags.
- Turn the key to ON
- Depress A/C and RECIRC at the same time and turn the
temperature **** one click to the right.
- Keep holding the A/C and RECIRC buttons and all the stick
figure lamps will light up (lamp test)
- Release the buttons.
- Push either A/C or RECIRC once
Record the numbers that display.
00 = none or end of cycle.
There are other tests that can be done from the buttons but
for now just stop the test by turning the key off
I'll scan the pages for you but it will be later today.
Gotta go to work.
--
-- DougW -- 93 ZJ 4.0 http://members.***.net/wilsond
HESCO Supercharger - 300W IASCA Stereo - Edelbrock IAS Shocks
Gibson Exhaust - rear DCpower - custom gauge install - Stillen Rotors
04-08-2004, 07:49 AM
#7
Guest
Posts: n/a
Re: 93 GC heater/ AC fan on all the time problem
Walt Barie did pass the time by typing:
> Well, my heater / AC fan is now staying on all the time even with the
> key off. If I turn the control to HI I hear the high speed relay click
> and the fan actually goes a little bit faster so I don't think that it
> is a high speed fan relay problem. Searching the archives this appears
> to be the sign of a bad fan control module.
>
> My question is where is the fan control module located? Do I need to
> remove the glove compartment, pass side dash board, or can I get to it
> from underneath (or is it somewhere else completely?). Also can anyone
> describe it so that I know what I am looking for. Oh and my GC has the
> automatic climate control system.
>
> Any help would be appreciated.
Yep. More than likely the power module.
You can pull Fuse 11 (30A in the distribution center
behind battery) And that will remove power to the system.
Run the ATC diags.
- Turn the key to ON
- Depress A/C and RECIRC at the same time and turn the
temperature **** one click to the right.
- Keep holding the A/C and RECIRC buttons and all the stick
figure lamps will light up (lamp test)
- Release the buttons.
- Push either A/C or RECIRC once
Record the numbers that display.
00 = none or end of cycle.
There are other tests that can be done from the buttons but
for now just stop the test by turning the key off
I'll scan the pages for you but it will be later today.
Gotta go to work.
--
-- DougW -- 93 ZJ 4.0 http://members.***.net/wilsond
HESCO Supercharger - 300W IASCA Stereo - Edelbrock IAS Shocks
Gibson Exhaust - rear DCpower - custom gauge install - Stillen Rotors
> Well, my heater / AC fan is now staying on all the time even with the
> key off. If I turn the control to HI I hear the high speed relay click
> and the fan actually goes a little bit faster so I don't think that it
> is a high speed fan relay problem. Searching the archives this appears
> to be the sign of a bad fan control module.
>
> My question is where is the fan control module located? Do I need to
> remove the glove compartment, pass side dash board, or can I get to it
> from underneath (or is it somewhere else completely?). Also can anyone
> describe it so that I know what I am looking for. Oh and my GC has the
> automatic climate control system.
>
> Any help would be appreciated.
Yep. More than likely the power module.
You can pull Fuse 11 (30A in the distribution center
behind battery) And that will remove power to the system.
Run the ATC diags.
- Turn the key to ON
- Depress A/C and RECIRC at the same time and turn the
temperature **** one click to the right.
- Keep holding the A/C and RECIRC buttons and all the stick
figure lamps will light up (lamp test)
- Release the buttons.
- Push either A/C or RECIRC once
Record the numbers that display.
00 = none or end of cycle.
There are other tests that can be done from the buttons but
for now just stop the test by turning the key off
I'll scan the pages for you but it will be later today.
Gotta go to work.
--
-- DougW -- 93 ZJ 4.0 http://members.***.net/wilsond
HESCO Supercharger - 300W IASCA Stereo - Edelbrock IAS Shocks
Gibson Exhaust - rear DCpower - custom gauge install - Stillen Rotors
04-08-2004, 07:49 AM
#8
Guest
Posts: n/a
Re: 93 GC heater/ AC fan on all the time problem
Walt Barie did pass the time by typing:
> Well, my heater / AC fan is now staying on all the time even with the
> key off. If I turn the control to HI I hear the high speed relay click
> and the fan actually goes a little bit faster so I don't think that it
> is a high speed fan relay problem. Searching the archives this appears
> to be the sign of a bad fan control module.
>
> My question is where is the fan control module located? Do I need to
> remove the glove compartment, pass side dash board, or can I get to it
> from underneath (or is it somewhere else completely?). Also can anyone
> describe it so that I know what I am looking for. Oh and my GC has the
> automatic climate control system.
>
> Any help would be appreciated.
Yep. More than likely the power module.
You can pull Fuse 11 (30A in the distribution center
behind battery) And that will remove power to the system.
Run the ATC diags.
- Turn the key to ON
- Depress A/C and RECIRC at the same time and turn the
temperature **** one click to the right.
- Keep holding the A/C and RECIRC buttons and all the stick
figure lamps will light up (lamp test)
- Release the buttons.
- Push either A/C or RECIRC once
Record the numbers that display.
00 = none or end of cycle.
There are other tests that can be done from the buttons but
for now just stop the test by turning the key off
I'll scan the pages for you but it will be later today.
Gotta go to work.
--
-- DougW -- 93 ZJ 4.0 http://members.***.net/wilsond
HESCO Supercharger - 300W IASCA Stereo - Edelbrock IAS Shocks
Gibson Exhaust - rear DCpower - custom gauge install - Stillen Rotors
> Well, my heater / AC fan is now staying on all the time even with the
> key off. If I turn the control to HI I hear the high speed relay click
> and the fan actually goes a little bit faster so I don't think that it
> is a high speed fan relay problem. Searching the archives this appears
> to be the sign of a bad fan control module.
>
> My question is where is the fan control module located? Do I need to
> remove the glove compartment, pass side dash board, or can I get to it
> from underneath (or is it somewhere else completely?). Also can anyone
> describe it so that I know what I am looking for. Oh and my GC has the
> automatic climate control system.
>
> Any help would be appreciated.
Yep. More than likely the power module.
You can pull Fuse 11 (30A in the distribution center
behind battery) And that will remove power to the system.
Run the ATC diags.
- Turn the key to ON
- Depress A/C and RECIRC at the same time and turn the
temperature **** one click to the right.
- Keep holding the A/C and RECIRC buttons and all the stick
figure lamps will light up (lamp test)
- Release the buttons.
- Push either A/C or RECIRC once
Record the numbers that display.
00 = none or end of cycle.
There are other tests that can be done from the buttons but
for now just stop the test by turning the key off
I'll scan the pages for you but it will be later today.
Gotta go to work.
--
-- DougW -- 93 ZJ 4.0 http://members.***.net/wilsond
HESCO Supercharger - 300W IASCA Stereo - Edelbrock IAS Shocks
Gibson Exhaust - rear DCpower - custom gauge install - Stillen Rotors
04-08-2004, 07:49 AM
#9
Guest
Posts: n/a
Re: 93 GC heater/ AC fan on all the time problem
Walt Barie did pass the time by typing:
> Well, my heater / AC fan is now staying on all the time even with the
> key off. If I turn the control to HI I hear the high speed relay click
> and the fan actually goes a little bit faster so I don't think that it
> is a high speed fan relay problem. Searching the archives this appears
> to be the sign of a bad fan control module.
>
> My question is where is the fan control module located? Do I need to
> remove the glove compartment, pass side dash board, or can I get to it
> from underneath (or is it somewhere else completely?). Also can anyone
> describe it so that I know what I am looking for. Oh and my GC has the
> automatic climate control system.
>
> Any help would be appreciated.
Yep. More than likely the power module.
You can pull Fuse 11 (30A in the distribution center
behind battery) And that will remove power to the system.
Run the ATC diags.
- Turn the key to ON
- Depress A/C and RECIRC at the same time and turn the
temperature **** one click to the right.
- Keep holding the A/C and RECIRC buttons and all the stick
figure lamps will light up (lamp test)
- Release the buttons.
- Push either A/C or RECIRC once
Record the numbers that display.
00 = none or end of cycle.
There are other tests that can be done from the buttons but
for now just stop the test by turning the key off
I'll scan the pages for you but it will be later today.
Gotta go to work.
--
-- DougW -- 93 ZJ 4.0 http://members.***.net/wilsond
HESCO Supercharger - 300W IASCA Stereo - Edelbrock IAS Shocks
Gibson Exhaust - rear DCpower - custom gauge install - Stillen Rotors
> Well, my heater / AC fan is now staying on all the time even with the
> key off. If I turn the control to HI I hear the high speed relay click
> and the fan actually goes a little bit faster so I don't think that it
> is a high speed fan relay problem. Searching the archives this appears
> to be the sign of a bad fan control module.
>
> My question is where is the fan control module located? Do I need to
> remove the glove compartment, pass side dash board, or can I get to it
> from underneath (or is it somewhere else completely?). Also can anyone
> describe it so that I know what I am looking for. Oh and my GC has the
> automatic climate control system.
>
> Any help would be appreciated.
Yep. More than likely the power module.
You can pull Fuse 11 (30A in the distribution center
behind battery) And that will remove power to the system.
Run the ATC diags.
- Turn the key to ON
- Depress A/C and RECIRC at the same time and turn the
temperature **** one click to the right.
- Keep holding the A/C and RECIRC buttons and all the stick
figure lamps will light up (lamp test)
- Release the buttons.
- Push either A/C or RECIRC once
Record the numbers that display.
00 = none or end of cycle.
There are other tests that can be done from the buttons but
for now just stop the test by turning the key off
I'll scan the pages for you but it will be later today.
Gotta go to work.
--
-- DougW -- 93 ZJ 4.0 http://members.***.net/wilsond
HESCO Supercharger - 300W IASCA Stereo - Edelbrock IAS Shocks
Gibson Exhaust - rear DCpower - custom gauge install - Stillen Rotors
04-08-2004, 11:15 AM
#10
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.
