71 Vette - no "high" on blower fan issues
Thread Starter
Heel & Toe
Joined: Aug 2009
Posts: 16
Likes: 0
From: Gallatin TN
71 Vette - no "high" on blower fan issues
I have a 71 Vette (350 / 270hp, with a/c) that I have replaced the blower fan switch, the blower motor cutout relay, the main control in console, new engine harness, a/c harness, front wiring harness, but I still have no "high" speed on the blower fan.
I bought another piece, the blower motor resistor ( see this link for picture -
http://www.zip-corvette.com/ProductDetails/ProductDetails.aspx?pid={47db8b56-6c89-413f-9427-cbe240fb5251}&pname=63-79+Blower+Motor+Resistor&Referer=QUICK_S EARCH&Alias=1971%20blower%20relay&ptct=B S-SR&CTitle=&
but I cannot seem to find where this part actually goes. Can someone please let me know what else to check or what my problem may be ?
Thanks in advance...
Ronnie
I bought another piece, the blower motor resistor ( see this link for picture -
http://www.zip-corvette.com/ProductDetails/ProductDetails.aspx?pid={47db8b56-6c89-413f-9427-cbe240fb5251}&pname=63-79+Blower+Motor+Resistor&Referer=QUICK_S EARCH&Alias=1971%20blower%20relay&ptct=B S-SR&CTitle=&
but I cannot seem to find where this part actually goes. Can someone please let me know what else to check or what my problem may be ?
Thanks in advance...
Ronnie
Thread Starter
Heel & Toe
Joined: Aug 2009
Posts: 16
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From: Gallatin TN
71 fan motor no "high"
Did you look at the part I had in the posting ? If so, where does it go ? It is not the relay on top of the air box, I cannot figure out where it goes... I have a wiring diagram but it does not tell where the part is located. Let me know once you have looked at it. Thank you very much !!
Thread Starter
Heel & Toe
Joined: Aug 2009
Posts: 16
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From: Gallatin TN
71 fan motor not on high
.. absolutely no offense taken... I can check it again but it was brand new - part of the new wiring harness I installed. I put a new fuse in it when I put it in. I did not replace the horn relay - could this be the issue ?
Safety Car
Joined: Apr 2000
Posts: 3,802
Likes: 61
From: Wichita KS
If the fuse is good then it is likely the resistor in the top of the air box as mentioned previously.
cc
Last edited by CCrane65; Dec 20, 2009 at 01:47 AM.
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,118
From: Crossville TN
If there's a short in the wiring for that "Hi speed" blower fuse, a 'new' one will still blow immediately. Remove the fuse and check for continuity. If 'bad', find the short in the wiring and repair it. If 'good', you have an open circuit somewhere in the wiring or no power (+12v) going to the fuse.
Melting Slicks
Joined: Mar 2009
Posts: 3,126
Likes: 15
If you are still looking for where it is installed here is a picture of my '77. I do not know if yours is in same location but all blower resistors will be located in the "duct" where air flow will cool the coils. mds...
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Race Director
Joined: May 2006
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From: Dayton, Ohio
Is the blue wire going to the relay getting 12 volts when the switch is in the high position "AND" is the relay grounded ?
edit-the high blow bypasses the resistors
edit-the high blow bypasses the resistors
Last edited by ...Roger...; Dec 20, 2009 at 03:17 PM.
Safety Car
Joined: Apr 2000
Posts: 3,802
Likes: 61
From: Wichita KS
You do have 4 wires on the blower relay right? One black, one blue, one orange (12 gauge) and one purple (12 gauge).
The wires are connected in the following order as you are looking at the bottom of the relay:
Black
Purple
Blue Orange
You should have the bottom three wires in a single connector but mine was missing so I offer this information just in case.
cc
The wires are connected in the following order as you are looking at the bottom of the relay:
Black
Purple
Blue Orange
You should have the bottom three wires in a single connector but mine was missing so I offer this information just in case.
cc
Race Director
Joined: May 2006
Posts: 16,528
Likes: 53
From: Dayton, Ohio
You do have 4 wires on the blower relay right? One black, one blue, one orange (12 gauge) and one purple (12 gauge).
The wires are connected in the following order as you are looking at the bottom of the relay:
Black
Purple
Blue Orange
You should have the bottom three wires in a single connector but mine was missing so I offer this information just in case.
cc
The wires are connected in the following order as you are looking at the bottom of the relay:
Black
Purple
Blue Orange
You should have the bottom three wires in a single connector but mine was missing so I offer this information just in case.
cc
But make sure the other end of the black wire is grounded through the blower ground. wiper,relay,blower all ground together through the black at the starter.
Le Mans Master
Joined: Aug 2006
Posts: 7,431
Likes: 1,561
From: mount holly NC
2025 c3 ('74-'82) of the Year Finalist - Unmodified
2019 C3 of Year Finalist (appearance mods)
My plug that goes to the (relay) in the top of the picture, is melted. Where can I get a new one?
Race Director
Joined: May 2006
Posts: 16,528
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From: Dayton, Ohio
Le Mans Master
Joined: Aug 2006
Posts: 7,431
Likes: 1,561
From: mount holly NC
2025 c3 ('74-'82) of the Year Finalist - Unmodified
2019 C3 of Year Finalist (appearance mods)
Thread Starter
Heel & Toe
Joined: Aug 2009
Posts: 16
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From: Gallatin TN
OK, I've checked and the fuse is good AND I have positive current coming from the orange wire coming from the horn relay. Is there any thing else I can check ?
Thread Starter
Heel & Toe
Joined: Aug 2009
Posts: 16
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From: Gallatin TN
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,118
From: Crossville TN
No. The resistor pack is not in the circuit when the blower is on "High" speed. If there is power to the 'input' side of that fuse, that means the blower switch and wiring up to the fuse are good. Your problem must be between the fuse and the blower motor. That leaves just the wiring between them and the blower relay. My bet is on the relay.
Thread Starter
Heel & Toe
Joined: Aug 2009
Posts: 16
Likes: 0
From: Gallatin TN
No. The resistor pack is not in the circuit when the blower is on "High" speed. If there is power to the 'input' side of that fuse, that means the blower switch and wiring up to the fuse are good. Your problem must be between the fuse and the blower motor. That leaves just the wiring between them and the blower relay. My bet is on the relay.