Electric Fan Wiring
 

I have a new Mr. Gasket Perma Cool Electric fan with sensor ready to mount up, Question is, can I just wire it to the battery with the 30 amp fuse in line or do I have to go to an on ignition source off the fuse block? Can anything be damaged by wiring it right to the battery? Any suggestions appreciated.

You can run it direct from battery as long as you have a fuse. But, without ignition switch involved it will work anytime. Engine on or off. You could run the battery down if you parked it and left it on.

I've had several of these after market auxillary electric fans, some with the supplied thermostats. If everything always worked as it was supposed to, you could wire directly to the battery and have the thermostat turn the thing off and on as needed. NONE of the thermostats I've had (they stick a probe into the radiator) have worked for very long, maybe a month or two.

What I would do and have done is put in a relay to the electic fan allowing activation only when the ignition swith is on. The main juice can still come directly form the battery conection and you can still have the thermostat in the circuit for however long it lasts. I just got a relay (30 amp) from Radio Shack or Pep Boys for $5-10.

With it wired directly to the battery and relying soley on the thermostat, you have to walk away with the fan still running and trust the thermostat to turn it off after it cools down enough. My experience says that those thermostats aren't reliable.

My advice is to wire the activator of the relay to the ignition switch, the main juice from the relay to the battery and forget the thermostat. Then you just turn it on as needed but it will only come on when the ignition switch is on.

Rev

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'66 Coupe, 306, 300 HP, C-4, 13.97 e.t., 100.3 mph
1/4 mi.

[This message has been edited by Rev (edited 08-13-2001).]

Hey Rev, Thanks for the info. This particular sensor actually butts up against the upper radiator hose near the stat, have you ever seen this type and know of it? I kind of like your idea with the seperate relay switch. Thanks

Rev is absolutely correct. When I first got my fans I had them wired directly to the battery and the thermo controlled them. After one week my battery was shot and could no longer hold a charge. And the relays do go bad very quickly due to the abuse or are just cheaply made. I get mine at Pep boys because it is close and can just pick up one when it goes out, not when it goes out. When you think of it having the fan on when the engine is off isn't helping you as much as you might think. Fans may be cooling but without waterpump turning you are only cooling the radiator not the engine.

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65 fastback
347 DFI injected, TFS heads, T5, 4.11 9", tc subframe conns, torq thrust D's
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