Help! A/C Fan stopped blowing.
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Joined: Mar 2015
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From: Frisco TX
Help! A/C Fan stopped blowing.
Hey evereyone,
So the other day I noticed my fan wouldn't turn up. I can power on the A/C and I can adjust the temperature and If I hold my hand to the vent I can feel hot or cold air, so i feel as if its working. However if I turn the fan up, nothing comes out. Almost as if the fan is locked up, or a fuse is blown, etc.
Not really sure where to start, HVAC is my least knowledgeable area. Is this someone that sound common or any ideas where I should begin?
Thanks in advance!
So the other day I noticed my fan wouldn't turn up. I can power on the A/C and I can adjust the temperature and If I hold my hand to the vent I can feel hot or cold air, so i feel as if its working. However if I turn the fan up, nothing comes out. Almost as if the fan is locked up, or a fuse is blown, etc.
Not really sure where to start, HVAC is my least knowledgeable area. Is this someone that sound common or any ideas where I should begin?
Thanks in advance!
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From: Frisco TX
You can start by telling us if the car has the manual HVAC system or the dual climate control HVAC. HUGE difference between the two systems as to how the blower motor is controlled.
If you look in the back of your owners manual you will see that fuse #51 in the passenger foot well fuse box is for the blower motor.
If you look in the back of your owners manual you will see that fuse #51 in the passenger foot well fuse box is for the blower motor.
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Joined: Mar 2015
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From: Frisco TX
If the fuse is OK then the problem is most likely the control module for controlling the fan. Here is a link that should help you:
https://www.corvetteforum.com/forums...post1580102173
Module attaches to the bottom of the HVAC plenum shown in post #19 in the 4th pic in post #19 with 3 sheet metal screws. May be a dealer only part but worth checking local parts stores anyway.
After carefully reviewing the pics in post #19 the very first pic shows the module installed. Note the pink and black wires with a plug that connects to the actual blower motor.
https://www.corvetteforum.com/forums...post1580102173
Module attaches to the bottom of the HVAC plenum shown in post #19 in the 4th pic in post #19 with 3 sheet metal screws. May be a dealer only part but worth checking local parts stores anyway.
After carefully reviewing the pics in post #19 the very first pic shows the module installed. Note the pink and black wires with a plug that connects to the actual blower motor.
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Joined: Mar 2015
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From: Frisco TX
Easy way to find out is to apply 12 volts to the motor. Used an appropriately fused connection. Motor pin that get the purple wire is the positive. Black is negative. Polarity determines the direction of rotation.
Fan motors do fail but there are far more instances reported on the Forum of the electronic controller smoking than the fan motor failing. YMMV
Fan motors do fail but there are far more instances reported on the Forum of the electronic controller smoking than the fan motor failing. YMMV
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From: Frisco TX
If you have the Dual Climate control unit as you said, there is NO resistor. The electronic control module in the first pic at the link above (Post #13 at that link) is what controls the fan motor. Functionally it is like the resistor pack that the manual HVAC system uses but it controls the fan based on electronic input from the HVAC control head. See the electrical diagram in post #15 of the link above....
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From: Frisco TX
I finally got around to tackling this project since I had the car in the shop for some time for another mechanical issue. After replacing fuses, it still does not work.
I can hear the A/C itself kick on when I press the cold-air button. But when I go to turn the fan up it doesn't do anything. No air at all comes out of the vents.
I'm assuming this would indicate the control module would need replaced? Just unsure since it looks to be in perfect shape. No copper lifting, cracking etc.
I can hear the A/C itself kick on when I press the cold-air button. But when I go to turn the fan up it doesn't do anything. No air at all comes out of the vents.
I'm assuming this would indicate the control module would need replaced? Just unsure since it looks to be in perfect shape. No copper lifting, cracking etc.
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From: Frisco TX
If the control module physically looks good then you should really start checking voltages in the circuit before spending the $$$ on a replacement module. I believe the climate control control module is fairly pricey and most places will not take back electrical/electronic components.
The link I provided in my post 5 above has electrical diagrams at post #13. The second diagram in post #13 is broken out a little better than the first. Beside checking fuse #27 I would check that there is voltage at the tan and red wires to the control module. If there is then with the control module plugged in check that there is voltage at the black and purple wire for the fan motor. You should also verify the integrity of Ground G202. Here are some links related to grounds that will help you with ground locations and what is grounded at each location:
http://forums.corvetteforum.com/c5-t...locations.html
http://forums.corvetteforum.com/c5-t...tion-long.html Post #1
Post back your results please......
The link I provided in my post 5 above has electrical diagrams at post #13. The second diagram in post #13 is broken out a little better than the first. Beside checking fuse #27 I would check that there is voltage at the tan and red wires to the control module. If there is then with the control module plugged in check that there is voltage at the black and purple wire for the fan motor. You should also verify the integrity of Ground G202. Here are some links related to grounds that will help you with ground locations and what is grounded at each location:
http://forums.corvetteforum.com/c5-t...locations.html
http://forums.corvetteforum.com/c5-t...tion-long.html Post #1
Post back your results please......
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From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
Here is the HVAC Schematic for dual climate control.
If you are blowing fuse # 51 it means one of the following is happening:
1. The blower motor is drawing a LOT more current than it was designed to. If you spin the rotor, it should spin freely. If it DRAGS or makes noises, the fan motor is bad. You can oil the motor rotor shaft bushings with some light machine oil to see if you can free it up if its difficult to turn. You have to take the blower motor out to do it properly. Oil the bushings through the hole where the rubber hose for cooling air connects to the motor.
2. The fuse that is blowing is making poor contact inside the fuse box holder. Use one of those OLD fuses. Snap a bad one in half and INSERT one of the fuse blades into the fuse holder. You should feel a nice tight insertion and removal mechanical resistance. If the fuse is loose in the fuse holder, it can cause this issue.
You really should get the overcurrent issue resolved before you damage that new fan controller..
Here is the HVAC Schematic for dual climate control.
If you are blowing fuse # 51 it means one of the following is happening:
1. The blower motor is drawing a LOT more current than it was designed to. If you spin the rotor, it should spin freely. If it DRAGS or makes noises, the fan motor is bad. You can oil the motor rotor shaft bushings with some light machine oil to see if you can free it up if its difficult to turn. You have to take the blower motor out to do it properly. Oil the bushings through the hole where the rubber hose for cooling air connects to the motor.
2. The fuse that is blowing is making poor contact inside the fuse box holder. Use one of those OLD fuses. Snap a bad one in half and INSERT one of the fuse blades into the fuse holder. You should feel a nice tight insertion and removal mechanical resistance. If the fuse is loose in the fuse holder, it can cause this issue.
You really should get the overcurrent issue resolved before you damage that new fan controller..
Here is the HVAC Schematic for dual climate control.