HVAC blower
Thread Starter
Burning Brakes
Joined: Aug 2010
Posts: 1,040
Likes: 1
From: Motorsports Capital of the World..Indianapolis Indiana
HVAC blower
98 coupe AT, dual digital climate control
OK so I have no blower fan when using my AC or heat.
I have no HVAC codes in DTC, I checked
I grounded out blower motor and it runs
I changed out BMCM with a supposed good used one
I have already searched all HVAC topics in forums
Now what, start ripping my dash apart to check wire continuity
or buy a new BMCM for $150 and hope that is it (probably be weeks for me to afford that)
Is there any way I can test BMCM to know it is bad?
Why did I buy a late 90's GM when my others in the 90's gave me electrical problems too
I just want to drive my car and enjoy it with some AC and defrost, It seems I can never win 
I don't have enough hair left to pull it out
Yeah I am sure someone will say take it to the stealership, ha ha I can't afford that unless I get a second job
OK so I have no blower fan when using my AC or heat.
I have no HVAC codes in DTC, I checked
I grounded out blower motor and it runs
I changed out BMCM with a supposed good used one
I have already searched all HVAC topics in forums
Now what, start ripping my dash apart to check wire continuity
or buy a new BMCM for $150 and hope that is it (probably be weeks for me to afford that) Is there any way I can test BMCM to know it is bad?
Why did I buy a late 90's GM when my others in the 90's gave me electrical problems too
I just want to drive my car and enjoy it with some AC and defrost, It seems I can never win I don't have enough hair left to pull it out
Yeah I am sure someone will say take it to the stealership, ha ha I can't afford that unless I get a second job
Tech Contributor
Joined: Jan 2007
Posts: 19,401
Likes: 1,143
From: Dyer, IN
98 coupe AT, dual digital climate control
OK so I have no blower fan when using my AC or heat.
I have no HVAC codes in DTC, I checked
I grounded out blower motor and it runs
I changed out BMCM with a supposed good used one
I have already searched all HVAC topics in forums
Now what, start ripping my dash apart to check wire continuity or buy a new BMCM for $150 and hope that is it (probably be weeks for me to afford that)
Is there any way I can test BMCM to know it is bad?
Why did I buy a late 90's GM when my others in the 90's gave me electrical problems too I just want to drive my car and enjoy it with some AC and defrost, It seems I can never win
I don't have enough hair left to pull it out
Yeah I am sure someone will say take it to the stealership, ha ha I can't afford that unless I get a second job
OK so I have no blower fan when using my AC or heat.
I have no HVAC codes in DTC, I checked
I grounded out blower motor and it runs
I changed out BMCM with a supposed good used one
I have already searched all HVAC topics in forums
Now what, start ripping my dash apart to check wire continuity
or buy a new BMCM for $150 and hope that is it (probably be weeks for me to afford that) Is there any way I can test BMCM to know it is bad?
Why did I buy a late 90's GM when my others in the 90's gave me electrical problems too
I just want to drive my car and enjoy it with some AC and defrost, It seems I can never win I don't have enough hair left to pull it out
Yeah I am sure someone will say take it to the stealership, ha ha I can't afford that unless I get a second job
Pro
Joined: Aug 2010
Posts: 545
Likes: 4
From: Calgary Alberta
So the positive was coming through the normal wire harness and you just provided a ground point? If so it would suggest to me that you need to look at splice pack 202 and ground point 202. Both the BMCM and the motor get there ground from that point. Both SP202 and G202 should be at the bottom of the A pillar just in front of the passenger door opening.
Thread Starter
Burning Brakes
Joined: Aug 2010
Posts: 1,040
Likes: 1
From: Motorsports Capital of the World..Indianapolis Indiana
Yes I have a GM service manual (all 2000+ pages) didn't have a lot of time to search through it
Yes I have a multimeter
Yes I can (barely) read schematics
Yes I checked all fuses
I will have to check out ground point 202 and splice pack 202 when I get time.
Thanks for all the help, any more ideas let me know.
I guess if it was a ground, I will have a spare BMCM for when it does fry.
I hope I find this problem soon, I have to replace the ground point for my radiator fans too, they work half the time, and the other half the time I have to get under hood and move wires by that ground point to get fans to come on.
Thanks guys
Yes I have a multimeter
Yes I can (barely) read schematics
Yes I checked all fuses
I will have to check out ground point 202 and splice pack 202 when I get time.
Thanks for all the help, any more ideas let me know.
I guess if it was a ground, I will have a spare BMCM for when it does fry.
I hope I find this problem soon, I have to replace the ground point for my radiator fans too, they work half the time, and the other half the time I have to get under hood and move wires by that ground point to get fans to come on.
Thanks guys
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Tech Contributor
Joined: Jan 2007
Posts: 19,401
Likes: 1,143
From: Dyer, IN
Yes I have a GM service manual (all 2000+ pages) didn't have a lot of time to search through it
Yes I have a multimeter
Yes I can (barely) read schematics
Yes I checked all fuses
I will have to check out ground point 202 and splice pack 202 when I get time.
Thanks for all the help, any more ideas let me know.
I guess if it was a ground, I will have a spare BMCM for when it does fry.
I hope I find this problem soon, I have to replace the ground point for my radiator fans too, they work half the time, and the other half the time I have to get under hood and move wires by that ground point to get fans to come on.
Thanks guys
Yes I have a multimeter
Yes I can (barely) read schematics
Yes I checked all fuses
I will have to check out ground point 202 and splice pack 202 when I get time.
Thanks for all the help, any more ideas let me know.
I guess if it was a ground, I will have a spare BMCM for when it does fry.
I hope I find this problem soon, I have to replace the ground point for my radiator fans too, they work half the time, and the other half the time I have to get under hood and move wires by that ground point to get fans to come on.
Thanks guys
"Under Diagnostic Information and Procedures"...there is a troubleshooting procedure for "Blower Motor Inoperative at Any Speed". That will isolate the issue. You have the bible....no need for guessing.....or parts changing.
Thread Starter
Burning Brakes
Joined: Aug 2010
Posts: 1,040
Likes: 1
From: Motorsports Capital of the World..Indianapolis Indiana
Ok, you have the service manual, but you have not done the troubleshooting......?
"Under Diagnostic Information and Procedures"...there is a troubleshooting procedure for "Blower Motor Inoperative at Any Speed". That will isolate the issue. You have the bible....no need for guessing.....or parts changing.
"Under Diagnostic Information and Procedures"...there is a troubleshooting procedure for "Blower Motor Inoperative at Any Speed". That will isolate the issue. You have the bible....no need for guessing.....or parts changing.
Thanks for pointing out my stupidity
Thread Starter
Burning Brakes
Joined: Aug 2010
Posts: 1,040
Likes: 1
From: Motorsports Capital of the World..Indianapolis Indiana
Followed the book diagnostics, only got to step 4 or 5.
Ground pack bad connection, wiggled ground pack, now it works so I will be going through the grounds this weekend.
Thanks for the help, I shoulda just looked at my book first.
and now I have a spare BMCM for if it ever goes out
Ground pack bad connection, wiggled ground pack, now it works so I will be going through the grounds this weekend.
Thanks for the help
, I shoulda just looked at my book first.and now I have a spare BMCM for if it ever goes out
Heel & Toe
Joined: Nov 2007
Posts: 21
Likes: 2
From: Chandler AZ
So the positive was coming through the normal wire harness and you just provided a ground point? If so it would suggest to me that you need to look at splice pack 202 and ground point 202. Both the BMCM and the motor get there ground from that point. Both SP202 and G202 should be at the bottom of the A pillar just in front of the passenger door opening.
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
I'm having a similar issue, except my AC blower cuts out at higher fan speeds. It works fine at lower fan speeds. I'm thinking I have the same problem. However, I don't have the service manual to reference. Can you provide more specifics as to where to find the ground point 202? Thanks in advance!
G202
Heel & Toe
Joined: Nov 2007
Posts: 21
Likes: 2
From: Chandler AZ
Thanks for all of the feedback and sorry for the slow response. I have a 2000 model year, manual transmission, with auto dual zone air controls.
The ground point seemed to make sense since I had the same issue last summer but only on the highest fan speed setting. A couple weeks ago I cranked the AC blower up and it cut out at both the highest and 2nd highest fan speed. So it seems to be progressing. I will check the ground point and report back what I find.
The ground point seemed to make sense since I had the same issue last summer but only on the highest fan speed setting. A couple weeks ago I cranked the AC blower up and it cut out at both the highest and 2nd highest fan speed. So it seems to be progressing. I will check the ground point and report back what I find.
Thread Starter
Burning Brakes
Joined: Aug 2010
Posts: 1,040
Likes: 1
From: Motorsports Capital of the World..Indianapolis Indiana
Anyone know which wire exactly in the Ground Pack is for the BMCM, I looked in my manual but I can't seem to find which wire it is, my ground problem is coming back occasionally. If I move the GP a little, the blower works fine for a day or two.
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
WHY,,,YES I DO!! 
Here is your blower schematic. Loom at pin "F" in the connector.
REMENBER!! Each ground connector comes apart and there are male and female pins inside that cause issues:
CORROSION
Here is your blower schematic. Loom at pin "F" in the connector.
REMENBER!! Each ground connector comes apart and there are male and female pins inside that cause issues:
CORROSION
Thread Starter
Burning Brakes
Joined: Aug 2010
Posts: 1,040
Likes: 1
From: Motorsports Capital of the World..Indianapolis Indiana
Thank you Bill Curlee.
I did take it apart and cleaned it all up when I had it removed due to a little corrosion on the pins and ground recepticals, but I may have to add a bypass (additional) ground wire looped off Pin F wire if I keep having problems.
BTW did you say schematic was posted?
I did take it apart and cleaned it all up when I had it removed due to a little corrosion on the pins and ground recepticals, but I may have to add a bypass (additional) ground wire looped off Pin F wire if I keep having problems.
BTW did you say schematic was posted?
Thread Starter
Burning Brakes
Joined: Aug 2010
Posts: 1,040
Likes: 1
From: Motorsports Capital of the World..Indianapolis Indiana
Anybody have a GM part number for these connectors if I wanna replace all mine that I have problems with, I would like to keep stock if possible, or if there is a better solution for new Ground packs.