Diagnosing Blower Stopage
Thread Starter
Instructor
Joined: Jun 2021
Posts: 213
Likes: 45
From: Georgia
Diagnosing Blower Stopage
Good morning all.
I am having an issue with my blower, and was hoping to get a little insight prior to starting my own diagnosing.
Here is what it is doing.
With either AC or Heat, the blower will randomly shut off on its own. It may turn back on in a couple seconds, may take five minutes, very random.
If I turn the blower switch off, the AC compressor will shut off, and if I turn it on, the compressor turns on, but no blower.
I'm thinking of three things, am I missing anything else that would be obvious to someone else?
- Switch (blower switch malfunction)
- Ground
- Blower motor is going out
I don't want to just throw money at the problem, and from what I have seen, changing out the blower motor is a bit of a task, so I'd save that for last if needed.
Thank you for any help or suggestions!
I am having an issue with my blower, and was hoping to get a little insight prior to starting my own diagnosing.
Here is what it is doing.
With either AC or Heat, the blower will randomly shut off on its own. It may turn back on in a couple seconds, may take five minutes, very random.
If I turn the blower switch off, the AC compressor will shut off, and if I turn it on, the compressor turns on, but no blower.
I'm thinking of three things, am I missing anything else that would be obvious to someone else?
- Switch (blower switch malfunction)
- Ground
- Blower motor is going out
I don't want to just throw money at the problem, and from what I have seen, changing out the blower motor is a bit of a task, so I'd save that for last if needed.
Thank you for any help or suggestions!
Thread Starter
Instructor
Joined: Jun 2021
Posts: 213
Likes: 45
From: Georgia
Burning Brakes
Joined: Oct 2001
Posts: 921
Likes: 200
From: TX
I was about to order a new blower on my 69. After removing it (painfully) I tested as calwldlife suggests above and it worked perfectly.
It was just a bad ground at the blower housing!!
Mine is the original and works perfectly. I bet yours does too! Your problem probably lies elsewhere.
VERYSOON
LETSGOBRANDON!
It was just a bad ground at the blower housing!!
Mine is the original and works perfectly. I bet yours does too! Your problem probably lies elsewhere.
VERYSOON
LETSGOBRANDON!
Thread Starter
Instructor
Joined: Jun 2021
Posts: 213
Likes: 45
From: Georgia
Thread Starter
Instructor
Joined: Jun 2021
Posts: 213
Likes: 45
From: Georgia
I was about to order a new blower on my 69. After removing it (painfully) I tested as calwldlife suggests above and it worked perfectly.
It was just a bad ground at the blower housing!!
Mine is the original and works perfectly. I bet yours does too! Your problem probably lies elsewhere.
VERYSOON
LETSGOBRANDON!
It was just a bad ground at the blower housing!!
Mine is the original and works perfectly. I bet yours does too! Your problem probably lies elsewhere.
VERYSOON
LETSGOBRANDON!
Le Mans Master
Joined: Jun 2019
Posts: 7,649
Likes: 2,466
From: Indiana
post your year? check relay and grounds..
this may help you
https://www.corvetteforum.com/forums...d-working.html
i also removed mine and it worked .. but it was shot.. no other reason as it has been flawless with new motor..see autopsy @VERYSOON post #9 so don't feel bad!
this may help you
https://www.corvetteforum.com/forums...d-working.html
i also removed mine and it worked .. but it was shot.. no other reason as it has been flawless with new motor..see autopsy @VERYSOON post #9 so don't feel bad!
Last edited by interpon; Nov 3, 2021 at 02:12 PM.
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Thread Starter
Instructor
Joined: Jun 2021
Posts: 213
Likes: 45
From: Georgia
I just cleaned all of my connections. Of course it is working again now. It is so intermittent that I won’t know for sure if it working until it stops working, if that makes sense.
However, after cleaning all of my connections, including the ground on the compressor, something new, I think, is happening.
While AC is running, every 10 seconds or so, the compressor clicks, and RPMS drop, and it’ll blow softer. Then, in only a few seconds without touching anything, RPMS climb back to normal, blows hard. Then about 10 seconds later, click, RPM drop, repeat repeat. What the heck have I gotten myself into! 😭 lol
However, after cleaning all of my connections, including the ground on the compressor, something new, I think, is happening.
While AC is running, every 10 seconds or so, the compressor clicks, and RPMS drop, and it’ll blow softer. Then, in only a few seconds without touching anything, RPMS climb back to normal, blows hard. Then about 10 seconds later, click, RPM drop, repeat repeat. What the heck have I gotten myself into! 😭 lol
Thread Starter
Instructor
Joined: Jun 2021
Posts: 213
Likes: 45
From: Georgia
post your year? check relay and grounds..
this may help you
https://www.corvetteforum.com/forums...d-working.html
i also removed mine and it worked .. but it was shot.. no other reason as it has been flawless with new motor..see autopsy @VERYSOON post #9 so don't feel bad!
this may help you
https://www.corvetteforum.com/forums...d-working.html
i also removed mine and it worked .. but it was shot.. no other reason as it has been flawless with new motor..see autopsy @VERYSOON post #9 so don't feel bad!
Team Owner
Joined: Jan 2007
Posts: 53,648
Likes: 878
From: Southern Cal Ca
St. Jude Donor '22
I just cleaned all of my connections. Of course it is working again now. It is so intermittent that I won’t know for sure if it working until it stops working, if that makes sense.
However, after cleaning all of my connections, including the ground on the compressor, something new, I think, is happening.
While AC is running, every 10 seconds or so, the compressor clicks, and RPMS drop, and it’ll blow softer. Then, in only a few seconds without touching anything, RPMS climb back to normal, blows hard. Then about 10 seconds later, click, RPM drop, repeat repeat. What the heck have I gotten myself into! 😭 lol
However, after cleaning all of my connections, including the ground on the compressor, something new, I think, is happening.
While AC is running, every 10 seconds or so, the compressor clicks, and RPMS drop, and it’ll blow softer. Then, in only a few seconds without touching anything, RPMS climb back to normal, blows hard. Then about 10 seconds later, click, RPM drop, repeat repeat. What the heck have I gotten myself into! 😭 lol
All A/Cs have these high low sensors.
If it is cold out that could explain the cycling.
If it is hot out, possible issues from "freon" amount,,,, low.
A good A/C on a hot day will run longer than it won't.
hope that makes sense.
Thread Starter
Instructor
Joined: Jun 2021
Posts: 213
Likes: 45
From: Georgia
means the A/C pressure sensors are telling the compressor to stop, then start.
All A/Cs have these high low sensors.
If it is cold out that could explain the cycling.
If it is hot out, possible issues from "freon" amount,,,, low.
A good A/C on a hot day will run longer than it won't.
hope that makes sense.
All A/Cs have these high low sensors.
If it is cold out that could explain the cycling.
If it is hot out, possible issues from "freon" amount,,,, low.
A good A/C on a hot day will run longer than it won't.
hope that makes sense.
Team Owner
Joined: Mar 2002
Posts: 44,645
Likes: 1,827
From: Huntsville AL
Circuit #40 ORN wire from inline 30amp fuse is the common side of the high speed relay.
1) Place blower switch to high, if you have 12V on DK BLU wire at blower relay than the switch is good.
2) With blower switch to high check for power at the blower relay ORN wire, if you have 12V the fuse is good.
3) With blower switch to high check for power at the blower relay PPL wire, if you have 12V the relay is good.
Outside of wire issues there are only 4 components in the HI Blower system. 1) Console switch, 2) 30A Fuse, 3) Blower Relay and 4) Blower Motor.
If the blower motor is working on lower settings the motor is good.
Thread Starter
Instructor
Joined: Jun 2021
Posts: 213
Likes: 45
From: Georgia
If this intermittent working and not working is happening on the high setting your problem is likely the fuse holder under the driver side fender. Not sure what year your car is, mine is a 73 and that's where its located.
Circuit #40 ORN wire from inline 30amp fuse is the common side of the high speed relay.
1) Place blower switch to high, if you have 12V on DK BLU wire at blower relay than the switch is good.
2) With blower switch to high check for power at the blower relay ORN wire, if you have 12V the fuse is good.
3) With blower switch to high check for power at the blower relay PPL wire, if you have 12V the relay is good.
Outside of wire issues there are only 4 components in the HI Blower system. 1) Console switch, 2) 30A Fuse, 3) Blower Relay and 4) Blower Motor.
If the blower motor is working on lower settings the motor is good.
Circuit #40 ORN wire from inline 30amp fuse is the common side of the high speed relay.
1) Place blower switch to high, if you have 12V on DK BLU wire at blower relay than the switch is good.
2) With blower switch to high check for power at the blower relay ORN wire, if you have 12V the fuse is good.
3) With blower switch to high check for power at the blower relay PPL wire, if you have 12V the relay is good.
Outside of wire issues there are only 4 components in the HI Blower system. 1) Console switch, 2) 30A Fuse, 3) Blower Relay and 4) Blower Motor.
If the blower motor is working on lower settings the motor is good.
I cleaned all of my connections it is running just fine at the moment. Not really sure if that has to do with cleaning everything up or just being intermittent as it is.
Now though, if it happens again, I have a bunch of really good info to go on. Which will be very helpful!
Edit to add: Mine is also a 73, would you be able to post a picture of that fuse holder? Thanks!
Last edited by Eric-; Nov 5, 2021 at 10:38 AM.
Team Owner
Joined: Mar 2002
Posts: 44,645
Likes: 1,827
From: Huntsville AL
Thank you sir. I appreciate the info. Right now it is working again. I have a feeling this is going to be a long term issue since I am not sure how to diagnose it not working, when it is working.
I cleaned all of my connections it is running just fine at the moment. Not really sure if that has to do with cleaning everything up or just being intermittent as it is.
Now though, if it happens again, I have a bunch of really good info to go on. Which will be very helpful!
Edit to add: Mine is also a 73, would you be able to post a picture of that fuse holder? Thanks!
I cleaned all of my connections it is running just fine at the moment. Not really sure if that has to do with cleaning everything up or just being intermittent as it is.
Now though, if it happens again, I have a bunch of really good info to go on. Which will be very helpful!
Edit to add: Mine is also a 73, would you be able to post a picture of that fuse holder? Thanks!
