climate control issues
Thread Starter
Intermediate
Joined: Nov 2008
Posts: 43
Likes: 0
From: Hardyville Virginia
climate control issues
Maybe someone has had this issue and can direct me to the source. The heater and ac works fine or ar least seems to in my 87 vette, but the blower motor doesn't seem to push the air hard enough. I can feel it increase and watch the numbers go up from 1 -10. The 87 has that automatic climate contol unit in it. I have a couple of questions: 1. Can this unit be taken out and updated with a setup from a newer C-4 like in the 90's where you have more control over it. 2. Should I try to but the blower on a seperate switch with a low medium and high. 3. Should I replace the whole unit with one like the current one. I am not really impressed with this automatic one due to not having control. Looking for advised and answers. Thanks Glenn
Le Mans Master
Joined: Dec 2000
Posts: 7,839
Likes: 22
From: San Diego, Ca
Jumper the blower motor directly to the battery and tell us if it improves.
'90 and up are different beasts in that the ECM takes over compressor engagement. You'd need a lot to pull it off and the dash controls may not fit your current configuration. I'd work on getting yours back to Factory. It's either got a weak Blower Motor, a worn out Blower Module, crappy wiring at the Blower (look for discoloration at the connector) or it's bleeding a bunch of air because the vent seals are shot. Not to hard to figure out once you jumper it to battery to see what it does.
'90 and up are different beasts in that the ECM takes over compressor engagement. You'd need a lot to pull it off and the dash controls may not fit your current configuration. I'd work on getting yours back to Factory. It's either got a weak Blower Motor, a worn out Blower Module, crappy wiring at the Blower (look for discoloration at the connector) or it's bleeding a bunch of air because the vent seals are shot. Not to hard to figure out once you jumper it to battery to see what it does.
Race Director
Joined: Oct 2005
Posts: 11,759
Likes: 175
From: Rolla Missouri
2021 C4 of the Year - Unmodified Finalist
St. Jude Donor '10 thru '25
The information in some of these threads might help.
http://forums.corvetteforum.com/c4-t...ower-89-a.html
http://forums.corvetteforum.com/c4-g...fan-speed.html
http://forums.corvetteforum.com/c4-t...e-control.html
http://forums.corvetteforum.com/c4-t...ower-89-a.html
http://forums.corvetteforum.com/c4-g...fan-speed.html
http://forums.corvetteforum.com/c4-t...e-control.html
Safety Car
Joined: Jul 2008
Posts: 3,966
Likes: 4
From: Made In America
St. Jude Donor '10-'11
Mine is VERY weak. I am about to replace the blower motor/blade..Will let you know if it improves. I highly doubt it will though...I have a feeling that C4s just naturally have no air flow like newer cars do....
Le Mans Master
Joined: Dec 2000
Posts: 7,839
Likes: 22
From: San Diego, Ca
Why not see if it's getting full voltage first? Assuming it's Electronic, the Blower hot wire (Red/Black or Purple) should have Battery at Auto 60 or 90. If not, measure the Dash input to the Blower Module (Brown) which should be 6 volts or better. If the Input is right, but the output is wrong; the Module is bad. If the Input is wrong, the Controls or wiring is bad. Also, the only way you get MAX (through '89) is at Auto 60/90. Manual 10 is not MAX - see your owner's Manual.
These things worked fine from the Factory and the same parts were used across the line - Chevy, Buick, Pontiac & Olds. That's not to say that they didn't break or that the engineering was real crisp - but out the door, airflow was more than adequate.
These things worked fine from the Factory and the same parts were used across the line - Chevy, Buick, Pontiac & Olds. That's not to say that they didn't break or that the engineering was real crisp - but out the door, airflow was more than adequate.
Drifting
Joined: Aug 2008
Posts: 1,921
Likes: 53
From: Philadelphia Pa
Why not see if it's getting full voltage first? Assuming it's Electronic, the Blower hot wire (Red/Black or Purple) should have Battery at Auto 60 or 90. If not, measure the Dash input to the Blower Module (Brown) which should be 6 volts or better. If the Input is right, but the output is wrong; the Module is bad. If the Input is wrong, the Controls or wiring is bad. Also, the only way you get MAX (through '89) is at Auto 60/90. Manual 10 is not MAX - see your owner's Manual.
These things worked fine from the Factory and the same parts were used across the line - Chevy, Buick, Pontiac & Olds. That's not to say that they didn't break or that the engineering was real crisp - but out the door, airflow was more than adequate.
These things worked fine from the Factory and the same parts were used across the line - Chevy, Buick, Pontiac & Olds. That's not to say that they didn't break or that the engineering was real crisp - but out the door, airflow was more than adequate.
Mechanical yes, electrical, no (I have changed a module or two, but that's about it).
Question: What do you mean by "Auto60/90"?. Also, I did think that the "Manual 10" was the max speed on the fan.
As I said, I won't touch the electricals, but I will take your suggestions to my mechanic and let him perform your suggested diagnostics. That way, I won't short out or kill a perfectly good and/or expensive part, which I have been notoriously known to do.
Steve
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Safety Car
Joined: Jul 2008
Posts: 3,966
Likes: 4
From: Made In America
St. Jude Donor '10-'11
