high speed on blower does not work
Thread Starter
Burning Brakes
Joined: Feb 2011
Posts: 829
Likes: 70
high speed on blower does not work
anyone know where the relay is on my 69 air conditioned vette for the highest speed? Could it be a resistor? There are two relays in the front part of the consol. either of those? tks
Instructor
Joined: Apr 2011
Posts: 167
Likes: 0
From: Jacksonville Florida
I don't know how similar my 77 is to your Vette but on mine the high speed is a different circuit from the other three speeds altogether. The relay on mine is above the evap box passenger side in the engine compartment. High speed has a different fuse than the other speeds. That might be worth checking. On mine it is a fuse link direct to the battery cable at the starter for high speed and a fuse in the fuse block for the others. Willcox might have a schematic for yours. That is where I found my schematic. Hope this helps!
Former Vendor
Joined: Aug 2006
Posts: 76,656
Likes: 1,850
From: Jeffersonville Indiana 812-288-7103
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15
Look on the firewall at the high blower relay.. See if the wire has come off. It is common for the wire connector at the relay to melt too.. so check that.
Here is a schematic that will help you: Look at Dark Blue wire in the connector.
Here is a different year.. better schematic from 1970.
Here is a schematic that will help you: Look at Dark Blue wire in the connector.
Here is a different year.. better schematic from 1970.
Last edited by Willcox Corvette; Jul 11, 2012 at 10:15 PM.
Le Mans Master
Joined: Aug 2001
Posts: 7,804
Likes: 4
From: Standing still with all my might Texas
Cruise-In X Veteran
St. Jude Donor '09-'11
There should be a thick orange wire attached to your horn relay (under the driver's side fender, close to the brake master cylinder). Follow that wire away from the horn relay and there should be a inline fuse holder. That is the fuse for your high blower. 
Edit: I may be wrong on the wire color. It might be a purple wire.
Edit: I may be wrong on the wire color. It might be a purple wire.
Thread Starter
Burning Brakes
Joined: Feb 2011
Posts: 829
Likes: 70
thanks for the advise. I tested the in-line fuse on the large orange wire and it is fine. The only relay near the fire wall has been replaced. The strange thing , is that I get power to all the leads on the resistor terminal with the lower fan speeds but no power on high.
I checked for loose and burned wires. no luck. There must be a separate relay for high speed. There are two relays (cans) in the front/inside of the console . No one seems to know what they do. HELP!
I checked for loose and burned wires. no luck. There must be a separate relay for high speed. There are two relays (cans) in the front/inside of the console . No one seems to know what they do. HELP!
Racer
Joined: May 2007
Posts: 370
Likes: 0
From: Cherry Hill N.J.
Check ground to starter wire, they burn and break frequently.....
Remove black ground wire from blower and run a test ground wire from a "Good" source.(frame or metal bracket)
If blower works with new ground.............you know the problem
Good Luck
Remove black ground wire from blower and run a test ground wire from a "Good" source.(frame or metal bracket)
If blower works with new ground.............you know the problem
Good Luck
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Race Director
Joined: May 2006
Posts: 16,528
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From: Dayton, Ohio
thanks for the advise. I tested the in-line fuse on the large orange wire and it is fine. The only relay near the fire wall has been replaced. The strange thing , is that I get power to all the leads on the resistor terminal with the lower fan speeds but no power on high.
I checked for loose and burned wires. no luck. There must be a separate relay for high speed. There are two relays (cans) in the front/inside of the console . No one seems to know what they do. HELP!
I checked for loose and burned wires. no luck. There must be a separate relay for high speed. There are two relays (cans) in the front/inside of the console . No one seems to know what they do. HELP!
So confirm the relay case is grounded , confirm you have power on the orange,confirm that the dk blue has power when the blower switch is on high position,then check the purple for power. Let us know what you find.
Former Vendor
Joined: Aug 2006
Posts: 76,656
Likes: 1,850
From: Jeffersonville Indiana 812-288-7103
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15
Go to the relay in the engine comp with the correct wires. What the relay is going to do is connect the orange wire to the purple wire to make the blower run on high. If the relay case has a ground provided by the 18 black and the 18 dk blue is made hot by the blower switch the relay will trip and connect the orange and purple.
So confirm the relay case is grounded , confirm you have power on the orange,confirm that the dk blue has power when the blower switch is on high position,then check the purple for power. Let us know what you find.
So confirm the relay case is grounded , confirm you have power on the orange,confirm that the dk blue has power when the blower switch is on high position,then check the purple for power. Let us know what you find.
And make sure that the wire is in the three wire connector good. The heat from the exhaust manifold dries them out, they crack and the will falls out.