1988 Climate Contoll Issue
Thread Starter
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1988 Climate Control Issue
Greetings all,
(I tried 8x's to attach a 25kb pict but, this site has problems again!)
Problem with a 1988 Corvette Coup...I haven't used the car in a bit and usually start it 2x's a month to keep things lubed and charged up, etc.....I wound up having to jump start the car with battery charger (starter-charger), 2-20-200) and I let it run for a bit.
I had a reason to use it and noticed that the ELECTRONIC CLIMATE CONTROL (CC) unit was acting up.......I could raise the displayed temperature (with the "up" button) in the digital window up as usual but, could not lower (with the "down" button) the temperature display at all, no matter where it was set at!
I have full control of the fan and all that but, not lowering the temperature...I have disconnected/bypassed the heater core quite some time ago in anticipation of replacing the core as I did my evaporator - just to be safe, and all still worked well after that.
I have read some info on replacing the "face" but, that is NOT an option as of yet...Is there a way to "re-set" the "CC" by a series of button pressings?...
I remember seeing that someplace but, not able to locate it......I HAVE disconnected the battery for 30 min with no change of issue....I also have NOT pulled the unit from dash to check on possible corroded contacts....
(I tried 8x's to attach a 25kb pict but, this site has problems again!)
Problem with a 1988 Corvette Coup...I haven't used the car in a bit and usually start it 2x's a month to keep things lubed and charged up, etc.....I wound up having to jump start the car with battery charger (starter-charger), 2-20-200) and I let it run for a bit.
I had a reason to use it and noticed that the ELECTRONIC CLIMATE CONTROL (CC) unit was acting up.......I could raise the displayed temperature (with the "up" button) in the digital window up as usual but, could not lower (with the "down" button) the temperature display at all, no matter where it was set at!
I have full control of the fan and all that but, not lowering the temperature...I have disconnected/bypassed the heater core quite some time ago in anticipation of replacing the core as I did my evaporator - just to be safe, and all still worked well after that.
I have read some info on replacing the "face" but, that is NOT an option as of yet...Is there a way to "re-set" the "CC" by a series of button pressings?...
I remember seeing that someplace but, not able to locate it......I HAVE disconnected the battery for 30 min with no change of issue....I also have NOT pulled the unit from dash to check on possible corroded contacts....
Last edited by Da Mail Man; Aug 10, 2019 at 10:34 AM.
Safety Car
Joined: Mar 2003
Posts: 3,583
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From: Indianapolis IN
Finalist 2020 C4 of the Year - Unmodified
C4 of Year Finalist (stock) 2019
99% of the time the symptoms your controller are exhibiting are caused from poor connections between the controller face and the controller board. I had similar problems on my '87 with C68. I took the controller out, disassembled it, cleaned the connectors on the board, carefully "re-formed" the connectors on the controller face to pinch more tightly on the board, put a very light coating of dielectric grease on the board terminals, then reassembled and tested. I never had any of those random intermittent "button-inop" conditions again.
I recall reading a thread where some have sent their controllers in the have each of the terminals hard-wire soldered to each of the controller face connectors. Unnecessary overkill in my opinion, but a solution that also works.
I recall reading a thread where some have sent their controllers in the have each of the terminals hard-wire soldered to each of the controller face connectors. Unnecessary overkill in my opinion, but a solution that also works.
Thread Starter
Safety Car
Joined: Jul 2004
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Likes: 30
Thanks for the reply.......I will probably wait for cooler weather here in Florida since the temps are 95* at present.....I am going to keep searching for the pages I read some time ago and I also believe I may have it on my computer but, could have lost it in a computer crash......It was some sort of series of buttons that placed the unit in a diagnostic mode.
Safety Car
Joined: Mar 2003
Posts: 3,583
Likes: 504
From: Indianapolis IN
Finalist 2020 C4 of the Year - Unmodified
C4 of Year Finalist (stock) 2019
No, on 90 and up the procedure for getting into diagnostic mode changed. Here's the procedure for getting into the earlier systems:
Press the Ext. Temp. button.
While pressing the Ext. Temp Button, press the Auto Fan button and then release it. Then release the Ext. Temp. button.
a -00 should appear. - indicating what Mode is displayed.
Mode 1 is Program number
Mode 2 is in vehicle thermistor
Mode 3 Ambient correction
Mode 4 Blower number
Mode 5 Outside thermistor
Mode 6 Feed back pot position
Mode 7 Calculated door position
Mode 8 System faults
Mode 9 Ratiometric feedback position
Mode 10 Full hot position
Mode 11 Full code position
Mode 12 Software version
To change Mode # press the Warm button.
To see the value in that Mode # press the Cool button.
A system fault will be indicated by a flashing indicator. If there is a problem with the ambient sensor, in
vehicle sensor, or the feedback potentiometer, the Ext. Temp. indicator will flash for about 60 seconds,
upon ignition ON. The flashing indicator will reoccur upon ignition ON until the system problem has been corrected.
Hope this helps!
Red--
Press the Ext. Temp. button.
While pressing the Ext. Temp Button, press the Auto Fan button and then release it. Then release the Ext. Temp. button.
a -00 should appear. - indicating what Mode is displayed.
Mode 1 is Program number
Mode 2 is in vehicle thermistor
Mode 3 Ambient correction
Mode 4 Blower number
Mode 5 Outside thermistor
Mode 6 Feed back pot position
Mode 7 Calculated door position
Mode 8 System faults
Mode 9 Ratiometric feedback position
Mode 10 Full hot position
Mode 11 Full code position
Mode 12 Software version
To change Mode # press the Warm button.
To see the value in that Mode # press the Cool button.
A system fault will be indicated by a flashing indicator. If there is a problem with the ambient sensor, in
vehicle sensor, or the feedback potentiometer, the Ext. Temp. indicator will flash for about 60 seconds,
upon ignition ON. The flashing indicator will reoccur upon ignition ON until the system problem has been corrected.
Hope this helps!
Red--
