Forgive me for my limited electronics knowledge, but I am in the middle of installing my black magic fan that i ordered from moes. If i do not wire the fan to a positive ignition source, the fan will continue to run when i turn the vehicle off. But it will only run untill the temp is below my desired setting correct...?

I suppose what I am asking is, do i need to have it wire to a positive ignition source or is the positive wire off the battery fine?

 

That is correct.

Off the battery is fine, if you do not mind it running with the key off. I prefer it this way, it allows you to shut the engine down and still continue cooling, handy if you tow heavy, race, or anything else where you would want to prevent heat-soak.

 

That is actually the RIGHT way to do it.

I din't, but I'm also running a 180* thermostat, so if my engine temp creeps up a little bit after shutting the engine down, no biggie, I still won't go up much past the 195* it would be with the stock t-stat. So I went with a switched power source. I guess I'm paranoid about the thing coming on and draining my battery, LOL...

 

Stock clutch fan only spins with the engine running, so you'll be fine to run it with the ignition source so it turns off with the ignition.

 

This is true, I originally wired mine "by the book", but I would never go inside until AFTER I heard my fan shut off. Usually did so in about 1-2 mins, but I got tired of gettin' skeeter bit in the evenings waiting till I heard my fan shut off...

 

Mine runs after the key is off but with having two batteries, i dont think it will kill mine easily....LOL

 

Mine switches off when I shut the motor off. Cooling systems were designed for that. The fan draws so much current, you pretty much have to go to the battery for fan juice. You can use a switched hot for the low-current side if you want.

 

I don't think amp draw is gonna be an issue for the OP. MY 180 Extreme only draws 18 amps and if I'm not mistaken, the Black Magic he has is somewhere down around 12 amps...

 

Yeah, I've been running mine, "un-switched", for over two years now without any battery issues, but I have to admit I was skeptical for the first month or so.