Is the (+) positive side of the coil a good 12 volt source?

[BaLleRz68]

Im wiring my electric fan soon and need a 12 volt/ignition source. Is the positive side of my MSD coil ok to use? Any thoughts are appreciated. Thanks.

 

[D.Hearne]

No, wire it to the battery directly. Fans draw too much power for them to share a terminal with something else.

 

[BlwnGazkit]

The coil only receives 12 volts while cranking, the rest of the time it's powered through a resistance wire.

So, NO, the coil is a bad place for a voltage source.

What part of the fan are you trying to wire? A relay or the fan itself? The fan needs to be run through a relay to prevent overloading any of the factory wiring. It wasn't designed to handle that amperage.

 

[BaLleRz68]

Thanks for the reply.I have the painless kit. Here is the link to the diagram.

http://www.painlessperformance.com/Manuals/30103Instruction.pdf

I need to find an "ignition/fan switch" source for the gray/white wire. I already spliced the ignition wire under the dash for my tach. Im just wondering if there is another source in the engine bay.

 

[Tim65GT]

I need to find an "ignition/fan switch" source for the gray/white wire. I already spliced the ignition wire under the dash for my tach. Im just wondering if there is another source in the engine bay.

Find a way through the firewall and attach it to the same ignition source as your tach. That would be best for your Fan relay operation.

The only other ignition source is to the + side of the coil, but it has the resistor wire in the path and is usually 6-9 Volts when running.

 

[rbohm]

that wire is for power to the trigger side of the relay, thus you can wire it directly to the battery. that way the fan will shut off when the engine temp has dropped to where the ground is disconnected. or if you want, you can use the stator terminal as you 12v power source, like the factory does with the electric choke.

 

[coupe5.0]

i wired mine into the alternator wiring, theres switched 12V there. Also used it to power the excitor wire on my 3G alternator conversion.

 

[Soaring1]

No, wire it to the battery directly. Fans draw too much power for them to share a terminal with something else.

Wrong. Electric fans need to be plugged into a fused block, and not the original fuse block that is 40 year old wiring. It also has to be a switched source for the 12V such as off of the ignition switch. Black with blue stripe if I remember correctly. If you hook that electric fan to the battery, it will run night and day. Not a real swift move.