wiring help

sweet66stang · 08-17-2002, 11:12 AM

I need to know the best place to hook up an electric fan to a wire thats only hot when the key is on

PKRWUD · 08-17-2002, 11:15 AM

The wire going to the pos. side of the coil is only hot when the key is ON. You could splice into it to use as a trigger wire for the fan relay.

Take care,
~Chris

Rev · 08-17-2002, 12:13 PM

I just ran mine to the starter relay. It has a terminal thats on when the ignition is on. It's right there on your passenger side fender apron on the '66. Now these fans draw a fair number of amps (10-15 ?), so I recommend using a 30 amp relay to activate the fan. That way, you don't have to run all that juice through the ignition switch. You can get that 30 amp relay for under $10 at PepBoys or Radio shack. I've had better luck with the ones from PepBoys. The relays come with wiring instructions.

Rev

sweet66stang · 08-17-2002, 02:31 PM

I contacted the company that makes the fan and they said to run it straight from an ignition only hot wire from my fuse box.. I did and it seems to be okay i let it run for about 10 minutes or so and let the motor get hot and the fan ran fine. so i think this shall work

Rev · 08-17-2002, 02:49 PM

That will probably work fine as long as you don't have to many after market accessories coming through the ignition switch. I have electric fuel pump, electric fan, electric choke, etc. as well as heater motor, AC, and future stereo demands that will need to be met. When you have those, believe me you won't want all that to go through the ignition switch.

Rev

PKRWUD · 08-17-2002, 03:00 PM

I completely disagree. I've never seen an electric fan manufacturer that didn't advise powering up through a relay. You're just asking for trouble. There should always be a relay involved with any high amp draw. It's very easy to hook up, and you still use an ignition hot wire to power it up, but you don't have excessive amps running through the cars wiring. Are you sure you understood their instructions? Who are "they"? What brand and model number fan is it?

Take care,
~Chris

Rev · 08-17-2002, 03:30 PM

The question is, can you stand and do you even want 10-15 more amps coming through your ignition switch wiring? I certainly do not.

Rev

sweet66stang · 08-17-2002, 04:26 PM

these are the instructions
flexalite sorry i had the wrong link before

Rev · 08-17-2002, 04:44 PM

The key words in that little post are "switched relay" and "can handle the load". If you want to overload the ignition switch, then be my guest. Wire it just the way you did.

Rev

PKRWUD · 08-17-2002, 10:56 PM

I can't believe they would suggest that, that's such a bad plan. If that's the way you want to do it, go for it, but you'll regret it big time. Not only are you running unnecessary amps through your ignition switch, but you are doing so in a much longer circuit than is necessary. Your going to be pulling 15+ amps from the battery, into the car, through the ignition switch, back into the engine compartment, and up to the fan. If you used a relay, the circuit carrying 15+ amps would go from the battery to the relay to the fan. Rather than going through 15 feet of wire and an ignition switch, it would go 3 feet, max. The longer the wire the amperage goes through, the thicker it needs to be. Otherwise, you run the very high risk of melting the insulation, and shorting out your electrical system.

In laymans terms, it would be like living in a duplex, with your front door right next to your neighbor, but instead of stepping a few feet to go from door to door, you build a bridge that crosses the street, and then build another to come back across the street.

It's your call, but if you want to do it your way, forget using the wires we've suggested. You need to run a heavy gauge wire from the fusebox.

Good luck.

Take care,
~Chris

Gearhead999 · 08-18-2002, 08:24 AM

Use a relay, you'll be glad you did.

08-17-2002, 11:12 AM	#1
sweet66stang Registered Member Join Date: Aug 2002 Posts: 8	wiring help I need to know the best place to hook up an electric fan to a wire thats only hot when the key is on

08-17-2002, 11:15 AM	#2
PKRWUD Junior Member Join Date: Mar 1999 Location: Ventura, California Posts: 8,981	The wire going to the pos. side of the coil is only hot when the key is ON. You could splice into it to use as a trigger wire for the fan relay. Take care, ~Chris __________________ Webmaster: Rice Haters Club Jim Porter Racing Peckerwoods Pit Stop Support Your Local RED & WHITE!

08-17-2002, 12:13 PM	#3
Rev Registered Member Join Date: Nov 1998 Location: Houston, Tx. Posts: 3,887	Relay I just ran mine to the starter relay. It has a terminal thats on when the ignition is on. It's right there on your passenger side fender apron on the '66. Now these fans draw a fair number of amps (10-15 ?), so I recommend using a 30 amp relay to activate the fan. That way, you don't have to run all that juice through the ignition switch. You can get that 30 amp relay for under $10 at PepBoys or Radio shack. I've had better luck with the ones from PepBoys. The relays come with wiring instructions. Rev __________________ '66 Coupe, 306, 350-375 HP, C-4, 13.07 e.t., 104.8 mph, 1/4 mi. O.B.C. #2 '66 coupe

08-17-2002, 02:49 PM	#5
Rev Registered Member Join Date: Nov 1998 Location: Houston, Tx. Posts: 3,887	Accessories That will probably work fine as long as you don't have to many after market accessories coming through the ignition switch. I have electric fuel pump, electric fan, electric choke, etc. as well as heater motor, AC, and future stereo demands that will need to be met. When you have those, believe me you won't want all that to go through the ignition switch. Rev __________________ '66 Coupe, 306, 350-375 HP, C-4, 13.07 e.t., 104.8 mph, 1/4 mi. O.B.C. #2 '66 coupe

08-17-2002, 03:00 PM	#6
PKRWUD Junior Member Join Date: Mar 1999 Location: Ventura, California Posts: 8,981	I completely disagree. I've never seen an electric fan manufacturer that didn't advise powering up through a relay. You're just asking for trouble. There should always be a relay involved with any high amp draw. It's very easy to hook up, and you still use an ignition hot wire to power it up, but you don't have excessive amps running through the cars wiring. Are you sure you understood their instructions? Who are "they"? What brand and model number fan is it? Take care, ~Chris __________________ Webmaster: Rice Haters Club Jim Porter Racing Peckerwoods Pit Stop Support Your Local RED & WHITE!

08-17-2002, 02:31 PM	#4
sweet66stang Registered Member Join Date: Aug 2002 Posts: 8	I contacted the company that makes the fan and they said to run it straight from an ignition only hot wire from my fuse box.. I did and it seems to be okay i let it run for about 10 minutes or so and let the motor get hot and the fan ran fine. so i think this shall work

08-17-2002, 03:30 PM	#7
Rev Registered Member Join Date: Nov 1998 Location: Houston, Tx. Posts: 3,887	10-15 more amps? The question is, can you stand and do you even want 10-15 more amps coming through your ignition switch wiring? I certainly do not. Rev __________________ '66 Coupe, 306, 350-375 HP, C-4, 13.07 e.t., 104.8 mph, 1/4 mi. O.B.C. #2 '66 coupe

08-17-2002, 04:26 PM	#8
sweet66stang Registered Member Join Date: Aug 2002 Posts: 8	these are the instructions flexalite sorry i had the wrong link before Last edited by sweet66stang; 08-17-2002 at 04:56 PM..

08-17-2002, 04:44 PM	#9
Rev Registered Member Join Date: Nov 1998 Location: Houston, Tx. Posts: 3,887	"key words" The key words in that little post are "switched relay" and "can handle the load". If you want to overload the ignition switch, then be my guest. Wire it just the way you did. Rev __________________ '66 Coupe, 306, 350-375 HP, C-4, 13.07 e.t., 104.8 mph, 1/4 mi. O.B.C. #2 '66 coupe

08-17-2002, 10:56 PM	#10
PKRWUD Junior Member Join Date: Mar 1999 Location: Ventura, California Posts: 8,981	I can't believe they would suggest that, that's such a bad plan. If that's the way you want to do it, go for it, but you'll regret it big time. Not only are you running unnecessary amps through your ignition switch, but you are doing so in a much longer circuit than is necessary. Your going to be pulling 15+ amps from the battery, into the car, through the ignition switch, back into the engine compartment, and up to the fan. If you used a relay, the circuit carrying 15+ amps would go from the battery to the relay to the fan. Rather than going through 15 feet of wire and an ignition switch, it would go 3 feet, max. The longer the wire the amperage goes through, the thicker it needs to be. Otherwise, you run the very high risk of melting the insulation, and shorting out your electrical system. In laymans terms, it would be like living in a duplex, with your front door right next to your neighbor, but instead of stepping a few feet to go from door to door, you build a bridge that crosses the street, and then build another to come back across the street. It's your call, but if you want to do it your way, forget using the wires we've suggested. You need to run a heavy gauge wire from the fusebox. Good luck. Take care, ~Chris __________________ Webmaster: Rice Haters Club Jim Porter Racing Peckerwoods Pit Stop Support Your Local RED & WHITE!

08-18-2002, 08:24 AM	#11
Gearhead999 Registered Member Join Date: Sep 1998 Location: Oviedo, FL Posts: 992	Use a relay, you'll be glad you did. __________________ "Support our Troops" Dave 1968 Cougar 2004 Thunderbird 2007 F150 Harley-Davidson, SuperCrew 1986 LTD 1997 Ranger 1992 Honda Civic

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