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Discussion Starter · #1 ·
I just hooked up a dual windstar fan setup, each fan is run off of a 30amp relay.

At the same time as I installed this fan I converted to a CS style alternator. Now I found that the 2 wires at the regulator that get connected to each other are only hot with the key on. This is what I wanted for the activation of my relays so I spliced into that wire. Then I ground the activation coil of the relay with a switch to turn the fans on/off.

The problem is if the car is not running only one relay will activate, and it's the relay for the smaller fan every time. If I unplug the heave guage wire for the smaller fan then the larger fan starts up when turned on. If both fans are plugged in and I turn them on, and then I tap the relay for the larger fan it will come on.

When the car is running both fans turn on ever time at the same time. Is it possible there just isn't enough current in that wire from the regulator I spliced into to activate the relays? Should I not have spliced into that wire?



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Chris Dagenais
Saskatchewan
'71 Malibu with a home built 454!
"Because of my velle, i'm broke, cut, bruised, tired, dirty, sweaty, and loving EVERY minute of it"
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If I got it right, it sounds like you hooked the alternator wiring to the +12v signal side of the relays. Usually these relays take almost nothing to turn them on.But if you are hooked to a circuit that goes through the alternator warning lamp, then you will get very little current. I suggest that you go directly to a known hot terminal, like the one on the horn relay or the terminal block next to the battery.
 

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Discussion Starter · #3 ·
Ok that's probably what my problem is. The thing is I am eventually going to be using a thermal switch to activate the fans, but I don't want them running while the car is off so I need to use a source that's only hot when the key is in the "on" position. Guess i'll have to find one somewhere else.



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Chris Dagenais
Saskatchewan
'71 Malibu with a home built 454!
"Because of my velle, i'm broke, cut, bruised, tired, dirty, sweaty, and loving EVERY minute of it"
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My relay's coil is driven off of the ignition post in my fuse box.

My single pole / double throw switchs controls the ground leg of the circuit. So I can send "it" through the thermo-swtich or straight to ground at my disgression. And in the middle is off




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71' 3880# with me. Big Block 402, TH400, 3.73 posi,
13.1sec @ 105 MPH (poor 2.1 sixty foot and rookie tuning)
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Gandalf80 (Chris);

Even if this wiring works, I'd not recommend it!! The wire that functions to energize the alternator is totally separate from any of the other "switched" 12 volt lines. The reason for this is to prevent possible back-feeding of the electrical system.

It may work, but if at some point in time you notice that the car doesn't want to turn off, keep this in mind.

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Wes. Vann
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Discussion Starter · #6 ·
Ya I was wondering how good of an idea it was to mess with that wire. Guess it was not the best choice! I'll be moving it to another switched source soon.



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Chris Dagenais
Saskatchewan
'71 Malibu with a home built 454!
"Because of my velle, i'm broke, cut, bruised, tired, dirty, sweaty, and loving EVERY minute of it"
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Gandalf
this will get your fans to run with the engine on only. Run a hot lead(low amp circut) from the battery to the relay then to your thermal switch(say one that closes at 185*) from the other pole of that switch run the lead to a oil pressure switch (one that closes when there is pressure) the other pole of that switch will be to ground. Now you have the control circut for your fan relay. Then just run your high amp circut from the battery to the relay to the fans.
Be sure to run the properly rated fuses for each circut

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Philip Mullaly
72 TPI El Camino
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