Topic: A/C Blower
in Forum: C3 Cooling and Heating Systems
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I have a strange problem with the fan in my 78'. The a/c fan works as it should on all speeds BUT high
. As soon as you turn it to high is slows to the same speed as it does in low. Anyone have any ideas?? I have installed a new resistor, relay, fan and a/c-heat control panel (all during the rebuild stage)
Thanks

Thanks

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moro, IL - USA
Joined: 2/11/2002
Posts: 406
Vette(s): 1979 Black coupe. 11256 original, documented, miles on it when I bought it in April of 2000. It now has 13100 on it. Oyster interior, like new. Everything original, everything works, except the clock. Paint has a couple of minor flaws.
|QUOTE|proudtexan said: I have a strange problem with the fan in my 78'. The a/c fan works as it should on all speeds BUT high
. As soon as you turn it to high is slows to the same speed as it does in low. Anyone have any ideas?? I have installed a new resistor, relay, fan and a/c-heat control panel (all during the rebuild stage)
Thanks
|/QUOTe
Paul,
When I bought my vette, I had the same problem. I just happened to work with a guy that had been a mechanic at a chevrolet garage. The first thing out of his mouth was, The connector on the firewall is fried. Bypass it. He said that is how they were instructed to do it.
Over the A/C duct on the firewall, there is a bundle of wires, and a single wire being fed by two wires. That connector on the single to two is fried. Cut it out, and solder the wires together. After I did mine, it worked like a champ.
It has been like that for 3 years, with no problem....
Let me know if it works for you.

Thanks

Paul,
When I bought my vette, I had the same problem. I just happened to work with a guy that had been a mechanic at a chevrolet garage. The first thing out of his mouth was, The connector on the firewall is fried. Bypass it. He said that is how they were instructed to do it.
Over the A/C duct on the firewall, there is a bundle of wires, and a single wire being fed by two wires. That connector on the single to two is fried. Cut it out, and solder the wires together. After I did mine, it worked like a champ.

Let me know if it works for you.
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Former Member
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BRADENTON, FL - USA
Joined: 8/4/2002
Posts: 669
Vette(s): 1972 convertible 350 auto trans, delux int, air, ps, pb, t/t wheel, pw, 79,000 org miles Rare one year only color
there is a resister assembly mounted to the heater box with a connector going to it. it's mounted on the heater box as to have air blowing over the resisters to cool them. there are 4 wires connected to it. its job is to control the speed of the fan. there are 3 resisters in this assembly, 1 for each speed. these resisters often quit indivually so that some speeds will work and not others. something to look into it is easy to replace
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Actually, there is a seperate relay for the High Speed Fan. Along with this relay is a fuse, approx. 1 foot from where the relay is located (relay is located in the engine compartment, in front of the blower motor). I replaced the relay, which was a waste of money, as I found the fuse, which was blown.
The High speed makes a ton of difference. 


1975/L48/Coupe/4 Speed(1 of 1057)/Headers/true duals/aluminum intake/holley 750/MSD ignition/roller rockers/
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in Forum: C3 Cooling and Heating Systems
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