A problem solved, and another puzzle occurs
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Team Owner
Joined: May 2005
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From: Huntsville AL
A problem solved, and another puzzle occurs
OK, I found the / a problem with the blower relay and resistor issues on my 82 Corvette. As a quick reminder, the blower motor would turn on WITH THE KEY OFF every time the blower motor was grounded.
It turns out that the A/C system was switched to the "NORM" position (not OFF) while all of this was occurring. The key was off, and the engine was not running, but it still seemed to be an issue. Once I switched the A/C from NORM to OFF, the blower motor immediately shut off until the key was turned ON. Then the blower motor behaved according to the switch position, except for the HI position. The blower motor does not run in the HI position.
Switching the A/C back to either "MAX" or "NORM" with the key OFF continued to turn the blower motor back on. That is the puzzle. Is this behavior normal for these cars? Is switching the A/C ON with the key OFF supposed to turn on the blower motor?
So, two questions ... Is this A/C ON with KEY OFF SUPPOSED to turn on the blower motor? and, what do I need to do to track down the reason that the high speed blower is not working properly?
Inquiring minds...
It turns out that the A/C system was switched to the "NORM" position (not OFF) while all of this was occurring. The key was off, and the engine was not running, but it still seemed to be an issue. Once I switched the A/C from NORM to OFF, the blower motor immediately shut off until the key was turned ON. Then the blower motor behaved according to the switch position, except for the HI position. The blower motor does not run in the HI position.
Switching the A/C back to either "MAX" or "NORM" with the key OFF continued to turn the blower motor back on. That is the puzzle. Is this behavior normal for these cars? Is switching the A/C ON with the key OFF supposed to turn on the blower motor?
So, two questions ... Is this A/C ON with KEY OFF SUPPOSED to turn on the blower motor? and, what do I need to do to track down the reason that the high speed blower is not working properly?
Inquiring minds...
Race Director
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From: Sunshine Coast, Queensland, Australia
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Key off. Blower motor does not run no matter where your switches are set. Period!
key on, blower motor continues run on low even with switches off.
high speed blower is a completely different circuit than the lower speeds.
key on, blower motor continues run on low even with switches off.
high speed blower is a completely different circuit than the lower speeds.
Last edited by 4-vettes; Mar 21, 2025 at 11:17 PM.
Race Director
Joined: Nov 2006
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From: Sunshine Coast, Queensland, Australia
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Blower motor wiring.
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From: New Or-leens Loo-z-anna
Rookie guess: use 4-vettes diagram to find why voltage is being supplied to the blower motor with the KEY OFF. Fix that problem first. The HIGH speed may begin to work properly once the first problem is corrected.
Race Director
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From: Sunshine Coast, Queensland, Australia
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Sounds to me like someone has done some rewiring work on this car in the past and is supplying power to the blower switch from a constant hot power source. You need to find this bit of rewiring and get the wiring connected properly to the proper power output from the fuse panel. As per the high speed power issue, could be a couple things. When it went weird in my car I found the plastic rivet that holds the electrical switch together had broken and the power switch only worked in some positions. This is the switch under the console connected to the slide lever that goes Max air, air heater, etc. On one side of that lever under the console is the vacuum switch, also held together with a plastic rivet and the flip side is the electrcal power switch.
Me, I'd start there. If the power switch there is ok and the speed switch basically next to it are ok. Then check for power on that red wire.
Me, I'd start there. If the power switch there is ok and the speed switch basically next to it are ok. Then check for power on that red wire.
Race Director
Joined: Nov 2006
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From: Sunshine Coast, Queensland, Australia
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Oh, and don't believe doorgunner, he ain't no Rookie!
Melting Slicks
Joined: Aug 2004
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From: Oakbank Manitoba
Stock operation:
Fan runs on "Low" speed all the time unless the fan speed switch is moved to a different position. Fan can't be turned off while the key is in run position. Only way to turn fan off is to move key to off position.
Moving the control slider to "OFF" does not turn off the fan.
With the key off the blower will not run when the control lever is moved to A/C positions (Max or Normal).
Conclusion:
Someone in the past has modified your HVAC wiring. Sounds like they didn't like the fact that the fan is always running on low. In the process they have screwed up the operation of the fan when set to "HIGH". In a stock car, the fan can be run on "High" two ways. One is by moving the blower speed switch to "High", the other is by sliding the control lever to "Max". All this is shown in the schematic. You need the assistance of someone to show you how the current flows in the schematic diagram.
In my opinion most of the issue will be with the wiring at the HVAC controls in the centre console. Look for signs of the wiring being modified/spliced. If you can't understand the schematic diagram then you will definitely need assistance from someone local to you.
Fan runs on "Low" speed all the time unless the fan speed switch is moved to a different position. Fan can't be turned off while the key is in run position. Only way to turn fan off is to move key to off position.
Moving the control slider to "OFF" does not turn off the fan.
With the key off the blower will not run when the control lever is moved to A/C positions (Max or Normal).
Conclusion:
Someone in the past has modified your HVAC wiring. Sounds like they didn't like the fact that the fan is always running on low. In the process they have screwed up the operation of the fan when set to "HIGH". In a stock car, the fan can be run on "High" two ways. One is by moving the blower speed switch to "High", the other is by sliding the control lever to "Max". All this is shown in the schematic. You need the assistance of someone to show you how the current flows in the schematic diagram.
In my opinion most of the issue will be with the wiring at the HVAC controls in the centre console. Look for signs of the wiring being modified/spliced. If you can't understand the schematic diagram then you will definitely need assistance from someone local to you.
Last edited by KENS80V; Mar 23, 2025 at 11:08 PM.
