electrical mystery
Thread Starter
6th Gear
Joined: Jun 2003
Posts: 6
Likes: 0
From: macungie pa
electrical mystery
My '97 HVAC fan turned on by itself the other day without the car running or the key in the ignition. When I pushed the fan speed button to the slowest speed, the A/C began running also without the car running and key in the ignition. In fact the key was in the house. I pulled all fuses that deal with HVAC and the fan kept running. Before I take the car to a dealer to be checked out, I was wondering if anyone had any thoughts on this. If not, an exorcism would be cheaper than taking the car to a dealer for repair.
Melting Slicks
Joined: Aug 2001
Posts: 3,050
Likes: 124
From: Wichita KS
Re: electrical mystery (cliffd)
An exorcist will not help in the Twilight Zone. :lol:
If you want to repair this yourself, you probably want access to a 1997 service manual and a scan tool.
That you have pulled all the HVAC fuses and the blower keeps working would indicate to me there is a short to voltage in one or more circuits. The 2003 service manual has a fault checklist for "Blower Motor Always On" and part of the fault analysis calls for a scan tool, and part calls for a test lamp connected to a good ground. I expect the 1997 manual has similar analysis tests. There are sections on circuit testing, etc.
The 2003 fault checklist has checks for shorts to voltage, poor connections, and the HVAC control module. Unfortunately, that paints the picture with a very broad brush. If some mods were done to the car that might have disturbed the wiring, that might be a place to look. Sorry not much help.
If you want to repair this yourself, you probably want access to a 1997 service manual and a scan tool.
That you have pulled all the HVAC fuses and the blower keeps working would indicate to me there is a short to voltage in one or more circuits. The 2003 service manual has a fault checklist for "Blower Motor Always On" and part of the fault analysis calls for a scan tool, and part calls for a test lamp connected to a good ground. I expect the 1997 manual has similar analysis tests. There are sections on circuit testing, etc.
The 2003 fault checklist has checks for shorts to voltage, poor connections, and the HVAC control module. Unfortunately, that paints the picture with a very broad brush. If some mods were done to the car that might have disturbed the wiring, that might be a place to look. Sorry not much help.
Burning Brakes
Joined: Dec 2000
Posts: 993
Likes: 5
From: Cincinnati Ohio
Re: electrical mystery (cliffd)
Refer to TSB 83-11-10 "Blower Motor Run On When Ignition is Off". It applies to the 1997 C5, and 1997 Buick Century and Regal.
To temporarily stop the bower motor from running, the TSB states to cycle the key to the "on" position.
As the permanent fix, it instructs the dealer to replace the heater a/c control head on the 1997 C5 with revised / updated part no. 09356081.
You can read the TSB here: http://corvetteactioncenter.com/kb/q....php?qstId=200
Good luck.
[Modified by 1999 White C5 Coupe, 7:34 AM 6/9/2003]
To temporarily stop the bower motor from running, the TSB states to cycle the key to the "on" position.
As the permanent fix, it instructs the dealer to replace the heater a/c control head on the 1997 C5 with revised / updated part no. 09356081.
You can read the TSB here: http://corvetteactioncenter.com/kb/q....php?qstId=200
Good luck.
[Modified by 1999 White C5 Coupe, 7:34 AM 6/9/2003]
