fan relay 12v igniton source
Thread Starter
Melting Slicks
Joined: Aug 2006
Posts: 3,429
Likes: 20
From: Kingston Ontario
fan relay 12v igniton source
Where's the best place under the hood to pull a 12v ignition source? Also, what is the best for my upgraded alternator, an extra wire to the starter or battery. I was going to run the extra wire to a terminal strip on the firewall and then to the battery. Does this wire require a fuse? That way I can pull the power for the fans off the terminal strip. Opinions?
Rob
Rob
Racer
Joined: Feb 2009
Posts: 330
Likes: 9
From: Las Vegas Nevada
Your way sounds like it might be better but I have my fans hooked directly to my alternator and I have them fused about 12 inches down the wires. My upgraded alternator is hooked up using all the same original wires. The wire between your starter (which goes directly to your battery) and alternator should be fused with a fuseable link. I still have the original fuseable link on my car, kind of surprised I have never popped it. My 12v ignition source is hooked to the wire that use to be used for my HEI.
Thread Starter
Melting Slicks
Joined: Aug 2006
Posts: 3,429
Likes: 20
From: Kingston Ontario
Your way sounds like it might be better but I have my fans hooked directly to my alternator and I have them fused about 12 inches down the wires. My upgraded alternator is hooked up using all the same original wires. The wire between your starter (which goes directly to your battery) and alternator should be fused with a fuseable link. I still have the original fuseable link on my car, kind of surprised I have never popped it. My 12v ignition source is hooked to the wire that use to be used for my HEI.
Racer
Joined: Feb 2009
Posts: 330
Likes: 9
From: Las Vegas Nevada
Pulling the high amperage power that way may be a good idea but what you want for a signal voltage to turn the fans on is an ignition source that is OFF when your key is in the Start position. That way if you are starting the car when it is hot the fans won't be using some of the power you need for the starter. I believe the voltage that enables the blower motor fan to run is a Run (on), Start (off) IGN source. You have me wondering about how I did mine years ago now. When I get home I will check and let you know.
Intermediate
Joined: Dec 2012
Posts: 48
Likes: 0
Power for my fans come from the starter up to a circut breaker then to the relay , ground from the fans go to the temp switch that controls on/ off, mines in the rt head. you can buy a kit for this on e-bay for about $30.00 good luck
Racer
Joined: Feb 2009
Posts: 330
Likes: 9
From: Las Vegas Nevada
BB72, the 12V IGN source on mine is coming from the center pin (yellow I think) of the WS wiper motor. This wire is only hot when in RUN position but in START it is not. The ground for the relays goes through my temp switch like racegofast.
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Drifting
Joined: Mar 2006
Posts: 1,263
Likes: 188
From: Wabasha Mn
To control my fans on my Ranchero I run an 8 gauge wire from the back of the alternator to a cole hersee constant duty marine solenoid. Then I run two 10 gauge wires, each with a circuit breaker to each fan. For the relay trigger wire I pull 12 volts from the ignition wire going to my HEI distributor. To ground the relay I use the temp switch that is in my thermostat housing. I like the heavy duty solenoid which is easier to wire than the standard bosch type small plastic relays. I use the same type of solenoid on my carbed 84 C4 to power my fuel pump circuit and a few other circuits.