electronic ignition
Senior User
Joined: Jul 2002
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From: baconton usa
electronic ignition
I seen a wiring diagram and got it pretty much figured out how to wire the duraspark system but one wire that goes to the coil it says it has to have a ballast resistor on it what does this look like where is it in the truck or can I just buy one is it a two wire hookup that I just put in line on the coil wire to the switch.
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Joined: Jun 1999
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From: Comox Valley, Canada
electronic ignition
The ballast resistor on the older Ford trucks is actualy a piece of resistor wire. It is in series with the wire to the coil + from the ignition switch. Depending on the year of your truck you most likely already have one.
The theory I have heard, and believe, about it is: it is used to reduce the running voltage to the coil to extend its life and the life of the points if the truck has points.
Sparky
The theory I have heard, and believe, about it is: it is used to reduce the running voltage to the coil to extend its life and the life of the points if the truck has points.
Sparky
Posting Guru
Joined: Jun 1999
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From: Comox Valley, Canada
electronic ignition
>it is a 79 f150 with electronic ignition I am going to put
>the 302 from that truck into a 67 and wanted to know how to
>wire it.
Does the 67 have all its original wiring, or better yet did you or are you removing the engine from it to install the 302???
The 67 should have all the wiring you require. Everything hooks up to the + of the "new" coil the same as to the old coil. All the other wires are in the duraspark harness on the 302.
You merely have to hookup two wires to the duraspark module.
A wire that has 12 volts when the key is held to "start" to the red wire. Could be a red/blue striped wire, if you cant find it run a new wire from the "I" terminal of the start relay.
And one that has 12 volts when the key is in "run" to the white wire. You will have to search around for a suitable wire, or tap into the igniton switch to get the correct 12 volts with key to "run" only.
Hope this explains it.
Sparky
>the 302 from that truck into a 67 and wanted to know how to
>wire it.
Does the 67 have all its original wiring, or better yet did you or are you removing the engine from it to install the 302???
The 67 should have all the wiring you require. Everything hooks up to the + of the "new" coil the same as to the old coil. All the other wires are in the duraspark harness on the 302.
You merely have to hookup two wires to the duraspark module.
A wire that has 12 volts when the key is held to "start" to the red wire. Could be a red/blue striped wire, if you cant find it run a new wire from the "I" terminal of the start relay.
And one that has 12 volts when the key is in "run" to the white wire. You will have to search around for a suitable wire, or tap into the igniton switch to get the correct 12 volts with key to "run" only.
Hope this explains it.
Sparky
Elder User
Joined: Jun 2002
Posts: 851
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From: Elizabeth City, NC
electronic ignition
Sparky,
I got one for ya. I spliced my resistance wire and am wondering if I did a big no no! What do you think?
Russell
1968 F250 LWB 300-6
FORD=First on Race Day
#88 Dale Jarrett
#21 Elliott Sadler
#97 Kurt Busch
#28 Ricky Rudd
I got one for ya. I spliced my resistance wire and am wondering if I did a big no no! What do you think?
Russell
1968 F250 LWB 300-6
FORD=First on Race Day
#88 Dale Jarrett
#21 Elliott Sadler
#97 Kurt Busch
#28 Ricky Rudd
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Posting Guru
Joined: Jun 1999
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From: Comox Valley, Canada
electronic ignition
Well, IMHO, if you didnt remove very much wire when you spliced it the change in resistance would be minimal. If you removed a large chunk of it.....well the voltage to the coil will be higher when it is running so it may "burn out" the coil quicker.
The factory resistance is supposed to be 1.05-1.15 ohms, well according to the book I have
So since I cant remember how long the wire is and if you have a rough idea.... divide the resistance by the wire length in inches to get a resistance per inch. Then measure the amount you removed and multiply it by the resistance you calculated per inch. Then subtract that from 1.15 and see how close it is to the 1.05-1.15 window.
Also with this type of wire you really have to have a good splice, dont want to have a higher resistance caused by a bad connection :-X23
Sparky
The factory resistance is supposed to be 1.05-1.15 ohms, well according to the book I have
So since I cant remember how long the wire is and if you have a rough idea.... divide the resistance by the wire length in inches to get a resistance per inch. Then measure the amount you removed and multiply it by the resistance you calculated per inch. Then subtract that from 1.15 and see how close it is to the 1.05-1.15 window.Also with this type of wire you really have to have a good splice, dont want to have a higher resistance caused by a bad connection :-X23
Sparky
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Brett Foote
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Joined: Jun 2002
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From: Elizabeth City, NC
electronic ignition
Thanks man. The insulation says "do not cut or splice" but I had no choice. Ignition switch is out of one truck and wire to coil is out of another. I had to take 2 bad harnesses and make one good one.
If it burns up the coil I will run my own wire with a 1 ohm resistor in series with it. Got plenty of those things sitting around the shop at work.
Russell
1968 F250 LWB 300-6
FORD=First on Race Day
#88 Dale Jarrett
#21 Elliott Sadler
#97 Kurt Busch
#28 Ricky Rudd
If it burns up the coil I will run my own wire with a 1 ohm resistor in series with it. Got plenty of those things sitting around the shop at work.
Russell
1968 F250 LWB 300-6
FORD=First on Race Day
#88 Dale Jarrett
#21 Elliott Sadler
#97 Kurt Busch
#28 Ricky Rudd
Posting Guru
Joined: Jun 1999
Posts: 2,415
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From: Comox Valley, Canada
electronic ignition
>If it burns up the coil I will run my own wire with a 1 ohm
>resistor in series with it. Got plenty of those things
>sitting around the shop at work.
Way better idea, IMHO anyway. I usually do this to the trucks I get. Had a resistor wire burn up once and took most of the other wires close to it out also. Boy did that truck ever do werid stuff before I figured out what happened. Turn on the key the wipers started, turn on signal lights radio came on :-X23 All that was left was one big black wire clump with everything shorted to everything where the harness behind the instrument panel used to be.
Make sure the resistor is able to handle the heat...that is why I use a Chrysler ballast reistor and carry a spare as they can be a little unreliable.
Sparky
Elder User
Joined: Jun 2002
Posts: 851
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From: Elizabeth City, NC
electronic ignition
> Way better idea, IMHO anyway. I usually do this to the
>trucks I get. Had a resistor wire burn up once and took most
>of the other wires close to it out also. Boy did that truck
>ever do werid stuff before I figured out what happened. Turn
>on the key the wipers started, turn on signal lights radio
>came on :-X23 All that was left was one big black wire clump
>with everything shorted to everything where the harness
>behind the instrument panel used to be.
> Make sure the resistor is able to handle the heat...that is
>why I use a Chrysler ballast reistor and carry a spare as
>they can be a little unreliable.
>
>Sparky
Thanks for the info. I know all about installing a too low wattage rated resistor. Took out a $40,000.00 circuit board doing that once. Oops. Thank goodness I was new to electronic's at the time! Anyways thanks for the info again. I think I may pull my resistor wire away from the bundle and run it outside from all the rest of 'em.
Later,
Russell
1968 F250 LWB 300-6
FORD=First on Race Day
#88 Dale Jarrett
#21 Elliott Sadler
#97 Kurt Busch
#28 Ricky Rudd
>trucks I get. Had a resistor wire burn up once and took most
>of the other wires close to it out also. Boy did that truck
>ever do werid stuff before I figured out what happened. Turn
>on the key the wipers started, turn on signal lights radio
>came on :-X23 All that was left was one big black wire clump
>with everything shorted to everything where the harness
>behind the instrument panel used to be.
> Make sure the resistor is able to handle the heat...that is
>why I use a Chrysler ballast reistor and carry a spare as
>they can be a little unreliable.
>
>Sparky
Thanks for the info. I know all about installing a too low wattage rated resistor. Took out a $40,000.00 circuit board doing that once. Oops. Thank goodness I was new to electronic's at the time! Anyways thanks for the info again. I think I may pull my resistor wire away from the bundle and run it outside from all the rest of 'em.
Later,
Russell
1968 F250 LWB 300-6
FORD=First on Race Day
#88 Dale Jarrett
#21 Elliott Sadler
#97 Kurt Busch
#28 Ricky Rudd