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I have a 72 ford that I put a 79 400 in with a Duraspark ignition I have found that I can wire in the red wire from the 2 wire plug on the ignition box to the Batt wire going to the coil. The wire I am not sure about is the white wire. I think I can tie it in to the red/blue wire that goes to the ignition switch.
Any help would be appreciated.
When I got the 79 it had a brown wire on the "I" this drawing says it s not needed.
The "S" only had 1 wire on it that's why I thought I should wire the white wire from the Duraspark to the red/blue on the ignition switch as that's where the "S" wire goes.
Red wire goes to the Run position from the ignition switch. The White wire doesn't have to be hooked up but would be better if it was. It's powered in the Start position from the ignition.
The purpose of the White wire is to retard the timing (internal function of the module) while the engine is cranking to lessen the load and stress placed on the starter.
Thanks Ultraranger,
I hate to be a pain but would you know what color the wires are on the ignition switch. The diagram I have shows the colors but not what they do. Me and wires not a good mix.
I just installed a Duraspark with a MSD coil and this was the way, I did mine since doing away earlier for a GM HEI dizzy that I just pulled out due to having some problems that , I never had before installing it. Now that since having straight 12v, I needed to use the resistor block Now it's all good
Hmm should have 12v at the coil while cranking & lowers to 6-8 volts running with the points system. Or while using a MSD 2 coil or a Duraspark setup.
Since, I had removed the resistor wire an installed a heavy #10 ga. wire.
I needed to mount a resistor block. I mounted the 1.8 ohm block on the fire wall which give me 6.8volts coming out of the coil an 10 volts going into it from the resistor block with 13.6 volts battery running voltage going into the resistor block .:
I just installed a Duraspark with a MSD coil and this was the way, I did mine since doing away earlier for a GM HEI dizzy that I just pulled out due to having some problems that , I never had before installing it. Now that since having straight 12v, I needed to use the resistor block Now it's all good
Not to get off subject but what problems did you have with your HEI set up. Just out of curiosity. That is what I have installed in my truck.
The shaft or it's bushing causing it to short the module when taking off from a stop.
It was like running out of gas for a 7-10 seconds. It stalled hard to restart then once got it going it restated ok.
The magnet pickup was the problems. then the damn vac advance went bad on it could not find the correct one as it was a guessing game what would fit. Bought a 75 -85 advance and it was the wrong one.. That I'm stuck with it online no returns 20 bucks so I'll stay with OEM ford parts that is an easy find & fit..
I put the HEI on C/List for 50bucks it's now fits but not the advance is not.
From this HEI
Back to a Duraspark
Hmm should have 12v at the coil while cranking & lowers to 6-8 volts running with the points system. Or while using a MSD 2 coil or a Duraspark setup.
Since, I had removed the resistor wire an installed a heavy #10 ga. wire.
I needed to mount a resistor block. I mounted the 1.8 ohm block on the fire wall which give me 6.8volts coming out of the coil an 10 volts going into it from the resistor block with 13.6 volts battery running voltage going into the resistor block .:
Orich
With the key in the run position but not running I get 12.7 volts then when I crank it over it drops to 10.0 volts at the coil. The truck has not run since I did a frame of restoration. I also did the 3G upgrade at the same time. I have the coil hooked up while checking the voltages. The wiring in the truck looks like factory no cuts or splices.
If you've got the old style ign. key switch that has the round pin terminals in the rear plug. These go bad and loose voltage while in the start mode.
This Makes it hard starting this condition mimics the older vehicles when they used a resistor block on the fire wall that went bad which also acts the same way as a failed ign. dizzy condensor.
The engine almost starts until you let off the key & it dies..
Just a few of the round plug terminals will look burnt or over heated. One small little terminal that is the by past circuit that carries the full battery 12.7 volt to the coil is the one that gets really cooked it expands when trying to start the engine not making good contact the causes lower starting voltage like what's possibly happing to you.
You can change this overto the new switch that has the flat blade terminals
Orich
This is the type that's good.
If you've got the old style ign. key switch that has the round pin terminals in the rear plug. These go bad and loose voltage while in the start mode.
This Makes it hard starting this condition mimics the older vehicles when they used a resistor block on the fire wall that went bad which also acts the same way as a failed ign. dizzy condensor.
The engine almost starts until you let off the key & it dies..
Just a few of the round plug terminals will look burnt or over heated. One small little terminal that is the by past circuit that carries the full battery 12.7 volt to the coil is the one that gets really cooked it expands when trying to start the engine not making good contact the causes lower starting voltage like what's possibly happing to you.
You can change this overto the new switch that has the flat blade terminals
Orich
This is the type that's good.
Thanks for the help Orich,
Mine is the flat blades like in the picture you shared. Except mine only has 6 blades with wires going to 5 of them. One set of wires are doubled up.
Thx, I will keep my fingers crossed on the hei. I got talked into it before looking into everything. Mine also has the advance eliminator on it. they are simple though.
