1990 fan blower
Le Mans Master
Joined: Jan 2006
Posts: 5,621
Likes: 206
From: Orlando FL
Check the connector on the blower motor control module which is on top of the evaporator box under the hood. Look to see if there are any broken or burnt wires, Check the pins in the connector for good connection and to see if any are burnt. This can cause it to run full speed.
And not sure about the 90, but there might be a in line fuse somewhere around the blower and evaporator box. If you do have the fuse and it opens, it will cause the blower to run full speed also.
** Missed the obvious. The blower module could be defective.
And not sure about the 90, but there might be a in line fuse somewhere around the blower and evaporator box. If you do have the fuse and it opens, it will cause the blower to run full speed also.
** Missed the obvious. The blower module could be defective.
Last edited by pcolt94; Dec 25, 2011 at 10:29 PM.
Le Mans Master
Joined: Aug 2000
Posts: 8,838
Likes: 31
From: Australia
In your identical question you asked ten minutes before this one 
http://forums.corvetteforum.com/c4-t...uck-on-hi.html
http://forums.corvetteforum.com/c4-t...uck-on-hi.html
Thread Starter
Cruising
Joined: Dec 2011
Posts: 11
Likes: 0
In your identical question you asked ten minutes before this one
http://forums.corvetteforum.com/c4-t...uck-on-hi.html
http://forums.corvetteforum.com/c4-t...uck-on-hi.html
Sorry about the 2 posts still learning the site....new module tried..all wires ok..connection ok..could not locate a fuse...thanks for the recommendations.
Le Mans Master
Joined: Aug 2000
Posts: 8,838
Likes: 31
From: Australia
Le Mans Master
Joined: Dec 2000
Posts: 7,839
Likes: 22
From: San Diego, Ca
'90 and up was moved to one of the Fuse Boxes. It's 5 amps usually labelled PGMR. Actual blower voltage is monitored by the Programmer which is a splice from the hot lead back to the Programmer. The 5 amp fuse protects that circuit and when it opens, the Blower runs on High and may run with the ignition off.
Burning Brakes
Joined: Apr 2009
Posts: 877
Likes: 0
From: Broken Arrow Oklahoma
'90 and up was moved to one of the Fuse Boxes. It's 5 amps usually labelled PGMR. Actual blower voltage is monitored by the Programmer which is a splice from the hot lead back to the Programmer. The 5 amp fuse protects that circuit and when it opens, the Blower runs on High and may run with the ignition off.
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Le Mans Master
Joined: Dec 2000
Posts: 7,839
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From: San Diego, Ca
If it's '90 or newer, sounds like the Module or Programmer or Controls - there isn't any Blower Relay for Electronic A/C. There should be a brown wire at the Module which carries the Low Voltage Signals from the Programmer. Range is about 2 (1) to 6 (10) volts. Output - purple or whatever is hot at the Blower should be 4 to 12 volts. If the Inputs are right, it's the Module. If the Inputs aren't what you've dialed in, it's either the Programmer or Panel. You'll need a bi-directional scanner with the right Cartridge hooked up to the CCM to troubleshoot either. That will emulate the Controls and if it works, you need a new Panel. If it doesn't, it's the Programmer. Should take all of 5 minutes at a Dealership if you don't have a Scanner - though they'll probably flat rate you an hour. If it's '89 or Below, the Processor is the Controls and if the inputs are wrong, you need a new or rebuilt Panel.
Burning Brakes
Joined: Apr 2009
Posts: 877
Likes: 0
From: Broken Arrow Oklahoma
If it's '90 or newer, sounds like the Module or Programmer or Controls - there isn't any Blower Relay for Electronic A/C. There should be a brown wire at the Module which carries the Low Voltage Signals from the Programmer. Range is about 2 (1) to 6 (10) volts. Output - purple or whatever is hot at the Blower should be 4 to 12 volts. If the Inputs are right, it's the Module. If the Inputs aren't what you've dialed in, it's either the Programmer or Panel. You'll need a bi-directional scanner with the right Cartridge hooked up to the CCM to troubleshoot either. That will emulate the Controls and if it works, you need a new Panel. If it doesn't, it's the Programmer. Should take all of 5 minutes at a Dealership if you don't have a Scanner - though they'll probably flat rate you an hour. If it's '89 or Below, the Processor is the Controls and if the inputs are wrong, you need a new or rebuilt Panel.
I guess I meant module, I bought a good one , I just haven't put it in.
I replaced the AC/Heater programmer last year.
Thanks.