HEI wiring change? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

steverino66 · 06-06-2007, 02:49 PM

I read somwhere the other day that a 'resistor wire' needs to be changed to wire HEI to an older stock harness. Can anyone clarify this - which wire exactly, and what does it need to change to? Any help appreciated.

1LoC10 · 06-06-2007, 02:53 PM

HEI runs off a constant 12 volt.... its needs a 12 volt wire, I just did the swap a few months ago and it runs great

hewlett2002000 · 06-06-2007, 03:31 PM

as did i. just take the wire off the stock coil on put it on the + terminal on the HEI.

CAL 58 GMC · 06-06-2007, 03:38 PM

1LoC10 is right. It's an easy install with only one 12 volt wire hooked up, that's what's nice about the HEI's, everything's all in one unit and all it need's is power hooked up to it.

Fred T · 06-06-2007, 04:20 PM

It is simple. All that is needed is a 14 or 12 gauge wire from the ignition side of the fuse block to the power on the HEI. You don't need the resistor or the bypass wiring from the starter.

hewlett2002000 · 06-06-2007, 05:21 PM

so does that mean i hooked mine up wrong? i just hooked the + wire from my old coil to my HEI. i thought the old coil got 12v?
thanks,
John

Fred T · 06-06-2007, 06:48 PM

Your HEI will work with the smaller wiring and resistor, but it will work better with the wiring change. Especially above 3,000 rpm.

The old coil got about 9 volts, which allowed the points to last longer. You can use and older coil with the HEI, but you need to lose the resistor to allow the HEI to function properly. The bigger gauge wire is because the HEI will demand more current at high rpm. For a V8 12 gauge, for a 6 14 ga is recommended.

hewlett2002000 · 06-06-2007, 06:58 PM

well in that case some rewiring is in order. thanks, i always thought the old coil got 12v.
thanks,
John

**Chevy Fleetside** · 06-06-2007, 07:00 PM

If it makes it easy you can just hook the HEI wire to the pink wire from your switch.. That carries 12 volts with the switch on..

hewlett2002000 · 06-06-2007, 10:51 PM

well i ran a wire to the ign on my fuse box. i just taped up the original so i could hide it. thanks for informing me of this yall.

hewlett2002000 · 06-07-2007, 06:06 AM

my truck seems to run better with it like that.

06-06-2007, 02:49 PM	#1
steverino66 Registered User Join Date: Oct 2005 Location: oklahoma Posts: 663	HEI wiring change? I read somwhere the other day that a 'resistor wire' needs to be changed to wire HEI to an older stock harness. Can anyone clarify this - which wire exactly, and what does it need to change to? Any help appreciated.

06-06-2007, 02:53 PM	#2
1LoC10 Insert Title Here Join Date: Feb 2006 Location: Dyer, Indiana Posts: 5,679	Re: HEI wiring change? HEI runs off a constant 12 volt.... its needs a 12 volt wire, I just did the swap a few months ago and it runs great __________________ BOBBY _69 SWB_ 1000 pics of 67-72's>> http://s193.photobucket.com/albums/z...-72/?start=all <<

06-06-2007, 03:31 PM	#3
hewlett2002000 Registered User Join Date: Dec 2006 Location: Cleveland, Tx Posts: 1,619	Re: HEI wiring change? as did i. just take the wire off the stock coil on put it on the + terminal on the HEI. __________________ Respect: 1. A feeling of appreciative, often deferential regard; esteem. 2. The state of being regarded with honor or esteem. 3. Willingness to show consideration or appreciation. When you fail to show consideration to others values you are showing disrespect.

06-06-2007, 03:38 PM	#4
CAL 58 GMC Senior Member Join Date: Jun 2005 Location: Clovis Ca. Posts: 3,311	Re: HEI wiring change? 1LoC10 is right. It's an easy install with only one 12 volt wire hooked up, that's what's nice about the HEI's, everything's all in one unit and all it need's is power hooked up to it. __________________ Classic Trucks Link http://www.classictrucks.com/feature...uck/index.html 1958 GMC.Project Build http://67-72chevytrucks.com/vboard/s...d.php?t=162816 1966 Chevelle Build http://67-72chevytrucks.com/vboard/s...d.php?t=443576 Video http://www.youtube.com/watch?v=prrNKo8F7Zw#GU5U2spHI_4

06-06-2007, 04:20 PM	#5
Fred T Cantankerous Geezer Join Date: Aug 2002 Location: Bel Aire, KS Posts: 6,264	Re: HEI wiring change? It is simple. All that is needed is a 14 or 12 gauge wire from the ignition side of the fuse block to the power on the HEI. You don't need the resistor or the bypass wiring from the starter. __________________ Fred There is no such thing as too much cam...just not enough engine.

06-06-2007, 05:21 PM	#6
hewlett2002000 Registered User Join Date: Dec 2006 Location: Cleveland, Tx Posts: 1,619	Re: HEI wiring change? so does that mean i hooked mine up wrong? i just hooked the + wire from my old coil to my HEI. i thought the old coil got 12v? thanks, John __________________ Respect: 1. A feeling of appreciative, often deferential regard; esteem. 2. The state of being regarded with honor or esteem. 3. Willingness to show consideration or appreciation. When you fail to show consideration to others values you are showing disrespect.

06-06-2007, 06:48 PM	#7
Fred T Cantankerous Geezer Join Date: Aug 2002 Location: Bel Aire, KS Posts: 6,264	Re: HEI wiring change? Your HEI will work with the smaller wiring and resistor, but it will work better with the wiring change. Especially above 3,000 rpm. The old coil got about 9 volts, which allowed the points to last longer. You can use and older coil with the HEI, but you need to lose the resistor to allow the HEI to function properly. The bigger gauge wire is because the HEI will demand more current at high rpm. For a V8 12 gauge, for a 6 14 ga is recommended. __________________ Fred There is no such thing as too much cam...just not enough engine.

06-06-2007, 06:58 PM	#8
hewlett2002000 Registered User Join Date: Dec 2006 Location: Cleveland, Tx Posts: 1,619	Re: HEI wiring change? well in that case some rewiring is in order. thanks, i always thought the old coil got 12v. thanks, John __________________ Respect: 1. A feeling of appreciative, often deferential regard; esteem. 2. The state of being regarded with honor or esteem. 3. Willingness to show consideration or appreciation. When you fail to show consideration to others values you are showing disrespect.

06-06-2007, 07:00 PM	#9
Chevy Fleetside Registered User Join Date: Sep 2006 Location: San Francisco Posts: 4,783	Re: HEI wiring change? If it makes it easy you can just hook the HEI wire to the pink wire from your switch.. That carries 12 volts with the switch on.. __________________ "A man and his truck, what a beautiful thing" 65 Short Fleetside BBC 65 Long Fleetside 283 3 on the tree for now. my build thread http://www.67-72chevytrucks.com/vboa...d.php?t=259536

06-06-2007, 10:51 PM	#10
hewlett2002000 Registered User Join Date: Dec 2006 Location: Cleveland, Tx Posts: 1,619	Re: HEI wiring change? well i ran a wire to the ign on my fuse box. i just taped up the original so i could hide it. thanks for informing me of this yall. __________________ Respect: 1. A feeling of appreciative, often deferential regard; esteem. 2. The state of being regarded with honor or esteem. 3. Willingness to show consideration or appreciation. When you fail to show consideration to others values you are showing disrespect.

06-07-2007, 06:06 AM	#11
hewlett2002000 Registered User Join Date: Dec 2006 Location: Cleveland, Tx Posts: 1,619	Re: HEI wiring change? my truck seems to run better with it like that. __________________ Respect: 1. A feeling of appreciative, often deferential regard; esteem. 2. The state of being regarded with honor or esteem. 3. Willingness to show consideration or appreciation. When you fail to show consideration to others values you are showing disrespect.



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