1970 f100 302 converting to electronic ignition

[junkyarddog82]

hi, im sure this has been discussed before, but im new here and couldn't fin the answers i was looking for.

i have a 1970 f100 shortbed 2wd. i just put a rebuilt 302 in it. i installed a 70s or 80s electronic distributor instead of going with a points distributor. i have had tons of 73-79 ford pickups so i have alot of parts left. i have ignition boxes, coils and wiring. this wiring obviously hooks right up on the late 70s fords. i can plug the coil in, plug the distributor in and plug the ignition box into this engine harness, so what i need to know is what do i need to wire upto the ignition box input to make this thing run on my 70. can i run anything from the connectors that stick out of my firewall near the gas pedal? do i need to go straight to the fuse box? any help is greatly appreciated. tell me where to run from and to. maybe someone has a couple pictures of their truck wired up? i can give you my email or post them on here. id like to start my truck in the next couple days. please help!

thanks in advance for any help.

[sargentrs]

Piece of cake. Just did it on my '70 302 last year. You should be using the ignition box with the blue "grommet" where the wires go into it. Coming out of the ignition box is a two prong male plug with a red wire and a white wire. That's the plug that's hard to find. Get some 12-14 ga wire (red and white) and a couple of female spade terminals with the plastic boots on them. You'll need about 6ft of red and about 10ft of white. Crimp the spade terminals on the wire leads you just cut. I put some dielectric grease on them beforehand to reduce corrosion. Stick the red wire to the red terminal and the white wire to the white terminal. Wrap the whole plug in electrical tape to make it waterproof and keep the terminals from pulling out. On the wiring plug on your ignition switch is a prong that has a fat pink wire and a thinner red wire coming out of the same prong. Depending on the orientation of your switch, mine was on the passenger end of the plug. Get one of those in-line clip on wiring joint things. Run the red wire from the ignition box and clip it on the thinner red wire, NOT the fat pink one (it's the resistor wire and you want to bypass it). This is a keyed hot in Start/Run position. Run the white wire from the ignition box to the "S" terminal on the starter solenoid on the fender. I used a ring terminal and a nut on mine to hold that wire on and clipped the original on the remaining end of the stud. Here's the reference I used on mine. http://www.therangerstation.com/tech_li ... arkII.html Fire it up and enjoy the ride!

[junkyarddog82]

thanks for the help and the link. sounds easy enough. hopefully i can get it wired up in the next couple days, filled up with oil and fire it up. thanks again. ill let you know how it goes.

[basketcase0302]

Here's another simple wiring diagram for the Duraspark:
http://www.fordification.com/forum/view ... =8&t=48178

[junkyarddog82]

I got all my parts gathered up but I have one question. I'm using the coil and wiring that clips over the end of the coil. The green wire goes into the spark box. The red wire, which I assume is the hot, goes into a plug in that my truck obviously doesn't have. Can I jut hook this wire to a switched power source, so it will be hot with the key coming on? Can I hook this wire onto the red wire from the ignition that I will be hooking the red wire from the spark box to? Or will that limit my power to the spark box? Please let me know what to do with the red wire that attaches to he cool, that's the only thing that I'm not sure about. Thanks

[sargentrs]

Can I hook this wire onto the red wire from the ignition that I will be hooking the red wire from the spark box to?

According to the wiring diagrams, yes. I left my original wiring in place and just ran a new wire in case I ever needed to go back to points.

[junkyarddog82]

Ok sounds good. But I have run into another dilemma. I got under the dash and was checking out the wires on the ignition switch. I found a pink wire all by itself. I found a red wire with a blue tracer. I found a lighter colored wire and a blue wire coming from the same terminal. Lighter wire could be yellow? Pink? A light color anyway. There was a few other wires too. I'm going to look for diagrams but any idea what's up with my ignition wires? Everything under the dash seems to be factory. Any ideas?

[basketcase0302]

The pink would have been the resistor wiring that fed the coil, (you don't want to use it to feed your Duraspark). There should be a wire that comes off of the same terminal on the ignition switch harness that you'd use to feed the Duraspark. Here's the wiring diagram on your year truck that might help:


And here's a wiring color chart that also might help. But I wouldn't take anything for granted, (I'd trace each wire to find the other end if possible).

[junkyarddog82]

i looked at the wiring diagrams for probably an hour last night. im going to go check my ignition again but im positive there wasnt another wire coming from the same terminal as the pink wire. also on the color code chart, it shows no red wire without a tracer. i am looking for a plan red wire correct? i don't remember seeing a plain red wire. were other years different?

im not sure what it is im missing, but if i can't come up with this red wire, is there another place i can tie my red ignition box wire into?ill try and get a picture of my ignition if i cant figure it out.

[sargentrs]

Interesting. I have replaced my ignition switch a couple of times in the past and mine's got the two wires coming into the same prong. Maybe it's an aftermarket thing? Regardless, it just needs to be a switched 12V connection. Doesn't particularly matter where it comes from. Use a voltmeter and check terminals for a 12V connection with the key in the ON position. On that wiring chart, 16A & B and 32 are possible candidates. You can also just pull out your ignition switch and check it at the harness plug and tag in there, if you want to keep it under the dash. Otherwise, you could go from the solenoid connection, up against the firewall and around to the box. I believe it's the "I" terminal that's 12V with key on. Can anybody confirm that? Other options are any accessory connection that's works when the key is turned on and doesn't work when it's turned off, like the radio connection.

[sargentrs]

Ok, so I just had one of those "DUH!" moments. I just pulled my wiring harness last Saturday. Here's a pic of the back side of my ignition switch showing where I clipped into the red wire beside the fat, pink, resistor wire, to run the hot to the Duraspark box. The blue connector on the wire is one of those clip on splices that has a built in male spade terminal in it. I put a female spade on the wire, connected it, and then clipped it around that wire.

[junkyarddog82]

I figured I could just find a switched 12v connection. So that's probably what I will do.

Here's another question. I was missing my connectors from the firewall for the temp and oil sending units so I went to a 69 parts truck I have. I pulled the harness and noticed it also includes the coil wire. So I plan on cutting it and connecting the red wire off my electronic coil to it. Is it possible to connect the ignition box wire onto that same wire? Will it take away voltage from my coil? Or should I just get the ignition box it's own source? I have everything I need to wire it up hopefully tomorrow so that's what I'm gonna do.

Also the harness on the firewall, that I mentioned above is a 3 prong plug. Beside it is a single plug that goes to a mechanism on the carb. Anyone know if this is a 12 volt source? I won't be using it to my carb, but if it's a constant 12 volt source I could connect it. Then if I need to remove it for any reason I can simply unhook it.

Sorry for all the questions to address in one, but I get to thinking as I'm staring at this truck and typing away. Thanks

[sargentrs]

Personally, I would give the ignition box it's own source and not mess with the source for the coil. The wire that goes to the carb is probably for an electric choke. This should be a keyed 12V source. A quick check with a voltmeter or test lead should confirm that. If so, and you're not going to use it for the electric choke, it would be a candidate for your ignition box source.

[junkyarddog82]

Ok thanks. I guess my plan of attack is to hook my coil wire to the existing could plug in on the firewall and shoot to hook the ignition box to the wire that goes to the carb. Thanks for all the help. I'm sure I'll be back for more advice. I'll keep you posted on how I make out with this wiring situation.

[basketcase0302]

Hope you don't mind that I copied and pasted from your other thread to save bandwidth...

junkyarddog82 on Fri Jun 08, 2012 5:12 pm i have b been working on my 70 f100 the past couple weeks. i actually just got some info on here about doing an electronic ignition conversion. today i was hooking stuff up so i could make sure the engine turned over by the key and i wanted to check out some of the lights. i guess that's where my problems started. here's whats going on:
all wiring is hooked up except my hot wire to my ignition box, which has nothing to do with this anyway.
i turn the key to the crank position and nothing happens.verify if there is 12 volts at the ignition switch
my headlights will light up
i do have turn signal problems and no brake lights. also my pass side taillight only works sometimes. but i can mess with the rear harness or change it with another one i have later. my main concern right now is figuring out why the engine wont crank from the key. the red and brown wires are in the correct location.do you mean the red and brown wires on the starter solenoid?
i wasn't sure if the ignition switch was a problem so i swapped with one out of a parts truck that i know worked 2 days ago. if anyone has any ideas please point me in the right direction. I've been looking at wiring diagrams and such and I'm not getting anywhere.
also my brain isn't working very well since I've been battling this wiring all day, and its been a long hot day. i planned on changing the turn signal switch because i have a feeling its bad. could this be contributing to my brake light problems, or is that more than likely my brake light switch.

Check for power to the brake light switch under the column for starters.