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Discussion Starter #1
my switch for my electric fans burns out about once a month. I even burned a 50amp switch. what does it mean when a elecrical connection gets really hot? does it need a better ground? or is it shorting out somewhere?

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Justin McIver
Sacramento CA
66-454-th350
 
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It means there is far to many amps flowing through the wire. The AC compressor was the number one amp hog on most cars, but 50 is way beyond the norm.

What kind of fans are you using?

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Wally
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Wow 50 amp fuse,
Yes it COULD mean all that, Switch, Fan, and Connections/Wiring.
First check to make sure you have good connects and a ground. If it still blows a 20 amp fuse then investigate the electric fan.
To troubleshoot the fan by running a wire directly from the fan to the (+) battery terminal with an in-line 20 amp fuse and a switch. Then run the (-)wire to a chassis ground. Run the engine to operating temperature. If the 20 amp fuse blows then I would seek a new electric fan.

Alway disconnect the (-) terminal of the battery before performing maintenance.

Hope this help.

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JR
70 396SS El Camino #'s Matching.
69 396SS Chevelle, project "Street Bruiser"
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72 Chevy C20 Flatbed, $500 DRMO sale. Thanks Uncle Sam
I live to own toyz...



[This message has been edited by SS396ELKY (edited 12-20-1999).]
 

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Sounds like the fan motor resistor circuit is shorting...The resistor circuit allows you to have multiple speeds..."high" on your switch bypasses the resistor circuit, while the lower speed settings lower the voltage going to the fan motor by running it through resistors...if your switch(es) stays cool(er) when the fan is on "high" then your resistor circuit is shorting out..

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When an electrical connection gets hot, it means there is more current passing through it than it is designed to handle, OR it is not a good clean tight connection (usually the case with stock wiring and hot connections).
I suggest you use a clamp on type ammeter to determine the amp load when the fan is running. 50 amps is way high :[ like ridiculous, and I think you are on the right track with the "short" idea, look for short circuits.
"Burning out" a 50 amp switch can be caused by several things such as VERY high current or way too much cycling on and off. If your fan constantly goes on and off, it will destroy the switch that does the turning on/off.
PS: what fan switch are you talking about ? the dash switch or thermal switch, or other ?

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Gotta have a Chevy !In Durham N.C.
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Justin...when you figure out what the problem is with that fan, you should also run a relay in the engine compartment, and not run the hot wire directly to the switch inside the car....Even at 20 or 25 amps, thats too much current to run through the firewall twice...use a relay, and save yourself some possible trouble later....
 

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Burning out a 50 amp switch?? why not let the thermostat drive relays that operate the fans? One relay for each fan should do it.
 

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If the switch you used is rated for 50 amps A/C service it will only handle 5 to 10 amps D/C. What kills a switch is the contacts burn when a switch is operated under load. With 60 cycle A/C the voltage is at 0, 120 times a second. As the contacts open the arc is snuffed when the voltage is at 0 potential. With D/C the contacts burn until the air gap is wide enough to stop the arcing. A switch designed for D/C service will have a wider air gap and faster action than one designed for A/C. Take the previous advice, install a temp switch and relay(s) to operate the fans.
 

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Discussion Starter #9
Ive had a temp. switch and it burned out too, so I just went back to the toggle.

I used one temp. switch for both fans(a dual flexalite unit) do you think it would solve my problems if I used two temp switches?

thanks for all of your help

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Justin McIver
Sacramento CA
66-454-th350
 
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