Any underhood location to tap [ignition on] 12v power source

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ximy
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Any underhood location to tap [ignition on] 12v power source

Post by ximy »

Hey Guys, I'm wanting an under hood [ignition on]12v distribution block for accessories now and future. Id like to have power for the tach, electric choke, etc. from this block.

Question: Is the a wire at the alternator or regulator where this is possible, rather than trying to tap in behind the ignition switch?

Image

I read this topic below (that taps behind ignition switch), thanks for the info.
http://www.fordification.com/forum/view ... ck#p667532
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Re: Any underhood location to tap [ignition on] 12v power source

Post by sargentrs »

I had an unconnected wire that laid on my intake alongside my valve cover on the driver side. It was either orange or brown, I can't remember, with a female bullet connector on the end. It went to some option I didn't have, the carb solenoid connection (see pic from wiring diagram). Turned out to be 12v switched. I always eyed it as a potential accessory connection in my engine bay.
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Re: Any underhood location to tap [ignition on] 12v power source

Post by waynek »

Will this switched source work to hook up ann electric choke? I have read the choke should be connected to the alternator stator because that connection will put out less than 12 volts.
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Re: Any underhood location to tap [ignition on] 12v power source

Post by sargentrs »

The electric choke I put on mine was spec'd at switched full 12v. Autozone special.
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1970 F100 Sport Custom Limited LWB, 302cid, 3 on the tree. NO A/C, NO P/S, NO P/B. Currently in 1000 pcs while rebuilding. Project thread: http://www.fordification.com/forum/view ... 22&t=59995 Plan: 351w, C4, LSD, pwr front disc, p/s, a/c, bucket seats, new interior and paint.
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Re: Any underhood location to tap [ignition on] 12v power source

Post by Mancar1 »

sargentrs wrote:The electric choke I put on mine was spec'd at switched full 12v. Autozone special.
Mine is hooked up in like manner. :thup:
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Re: Any underhood location to tap [ignition on] 12v power source

Post by waynek »

I have the electronic choke conversion shown in this link: http://www.carburetor-parts.com/Motorcr ... p_428.html

In the video, the connection wire is attached to the alternator stator. I'm wondering if using the 12volt source will work with this particular unit.
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Re: Any underhood location to tap [ignition on] 12v power source

Post by ximy »

waynek wrote:I have the electronic choke conversion shown in this link: http://www.carburetor-parts.com/Motorcr ... p_428.html

In the video, the connection wire is attached to the alternator stator. I'm wondering if using the 12volt source will work with this particular unit.
From what I hear the stator supplies 6v and not 12.

I am working on a solution. It is taping the oil pressure above the filter with an another on-off switch activated by oil pressure.

I'm making a simple wiring harness for this now. I will post pics when more parts get here.
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Re: Any underhood location to tap [ignition on] 12v power source

Post by motzingg »

the easiest place to tap it is on your coil (+) wire, but you might end up with issues if you start drawing a lot of current right through the ignition switch.

if you want to have lots of power for multiple accessories, best thing is to pull that wire from (+) coil and hook up a relay to deliver fatty current to the fuse block.

I found some nice Hella brand universal mount AGM fuse blocks, but none of them have built in relay sockets which i think would be real handy.

i'm going to end up cobbling something together myself.
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Re: Any underhood location to tap [ignition on] 12v power source

Post by 69Ford »

I'm a firm believer in not wiring up accessories into our wiring harnesses without using a relay. you are looking for problems later on. "ignition switch, Headlight switch and wiring burning up". Here's a pic of my setup. powered Fuse block wired of my battery decent gauge wire don't remember the gauge. one relay is for my ignition and the other is for my radio. I also use the LMC headlight wiring harness for the headlighs relayed high and low beams off this fuse block. These trucks were designed for the technology of the time.
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Re: Any underhood location to tap [ignition on] 12v power source

Post by ximy »

motzingg wrote:the easiest place to tap it is on your coil (+) wire, but you might end up with issues if you start drawing a lot of current right through the ignition switch.

if you want to have lots of power for multiple accessories, best thing is to pull that wire from (+) coil and hook up a relay to deliver fatty current to the fuse block.

I found some nice Hella brand universal mount AGM fuse blocks, but none of them have built in relay sockets which i think would be real handy.

i'm going to end up cobbling something together myself.
From what i hear you're not suppose to use power supplied to the coil, the coil need all it's power, and apparently some coils use 9v instead of 12. :hmm:
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Re: Any underhood location to tap [ignition on] 12v power source

Post by ximy »

69Ford wrote:I'm a firm believer in not wiring up accessories into our wiring harnesses without using a relay. you are looking for problems later on. "ignition switch, Headlight switch and wiring burning up". Here's a pic of my setup. powered Fuse block wired of my battery decent gauge wire don't remember the gauge. one relay is for my ignition and the other is for my radio. I also use the LMC headlight wiring harness for the headlighs relayed high and low beams off this fuse block. These trucks were designed for the technology of the time.
Excellent set up! I hope to post some pics soon. I had to buy some brass fittings for the sender I am going to use.
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Re: Any underhood location to tap [ignition on] 12v power source

Post by 69Ford »

ximy wrote:
motzingg wrote:the easiest place to tap it is on your coil (+) wire, but you might end up with issues if you start drawing a lot of current right through the ignition switch.

if you want to have lots of power for multiple accessories, best thing is to pull that wire from (+) coil and hook up a relay to deliver fatty current to the fuse block.

I found some nice Hella brand universal mount AGM fuse blocks, but none of them have built in relay sockets which i think would be real handy.

i'm going to end up cobbling something together myself.
From what i hear you're not suppose to use power supplied to the coil, the coil need all it's power, and apparently some coils use 9v instead of 12. :hmm:
There are two types of coil's. Resister coils and non resister coils. At least in the 69 model year ford used the non resister coil that's why there is a resister wire to bring down the voltage to an acceptable voltage for the points. I believe between 6 and 9 volts so this would not be a good point for accessory's I also believe this is for all bumps but not sure. Also if you leave the key in the on position without the truck running the points and coil will be damaged and good chance your accessories to. The ignition switch in the ACC position will shut your accessories off if wired to the coil. The only time the coil has 12 volts is when the ignition switch is in the start position starter turning. I know to much info to think about.
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Re: Any underhood location to tap [ignition on] 12v power source

Post by ximy »

Here is what I am doing. Using a oil switch activated by pressure to get 12 running volts. Brass t-fittings and other parts used for adding the switch to the original one.
SWITCH02.jpg
Wiring assembly will provide 12 volts only when engine is running.I am going to attach the coil and the tach here.
SWITCH01.jpg
Just fits between pumps and under brackets.
SWITCH03.jpg
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Re: Any underhood location to tap [ignition on] 12v power source

Post by motzingg »

[/quote]There are two types of coil's. Resister coils and non resister coils. At least in the 69 model year ford used the non resister coil that's why there is a resister wire to bring down the voltage to an acceptable voltage for the points. I believe between 6 and 9 volts so this would not be a good point for accessory's I also believe this is for all bumps but not sure. Also if you leave the key in the on position without the truck running the points and coil will be damaged and good chance your accessories to. The ignition switch in the ACC position will shut your accessories off if wired to the coil. The only time the coil has 12 volts is when the ignition switch is in the start position starter turning. I know to much info to think about.[/quote]


yeah good call... i'm running Duraspark and forgot that some trucks have the ballast resistor on the PINK wire in run.
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