How do I wire the coil?
 

I have a 1955 f250 that I've been working on and I am about to wire it up and try starting it. I'm wondering what side of the coil do I run to the Dist? Here's the details on it

12v Conversion w/ neg ground
motor is an early 60's 292 (not sure exactly what year)
12v starter relay
12v coil
12v points & Condenser
Original Ignition Switch
New correctly color coded wiring throughout

I have an external coil resistor for a 58. Where do i wire that in? :confused:

I don't want to fry the coil out so any help would be greatly appreciated.:-huh

Google painless wiring they did have wiring diaghrams on their site you should be able to use a basic Ford schematic. When I get home I will see if I can scan the sheet with the ignition wiring on it for you its from EZ wiring.

Is the 55 a 12V negative ground system?

If so then the negative side of the coil gets wired to the points in the distributor. The positive side of the coil gets fed through the ignition switch. Typically the positive side of the coil will run through a ballast resistor that cuts the 12V signal down to approx 5V. If this is the case then there is probably a "starting bypass" circuit which will feed the coil straight battery voltage when the starter is engaged.

Do you have the 4 terminal starter solenoid? if so the small terminal closest to the cable down to the starter is the feed for the coil.......I think

Bobby

The dist. should be connected to the ground side of the coil. In your case, negative for negative ground vehicles. Positive for positive ground vehicles. This terminal is shorted to ground every time the points close.

The other terminal of the coil has power applied when the ignition switch is in the run or start positions. In some applications the voltage on this terminal is reduced in the run position by an inline resistor. This is done to extend the life of the points. Full battery voltage is applied in the start position for a hotter spark.

Rick

Sorry Bobby. I didn't see your post before I posted mine. Too slow a typer I guess.

Rick

He did say he had a 12V neg. ground conversion. the terminal you are referring to is the ballast resister bypass and is only energized durring cranking the engine. it sould go to the positive terminal on the coil as well as the source from the ignition switch which sould come through a ballast resistor or a resistance wire link. the points will not last very long without the resistor in the circuit. the bypass from the solenoid is used to compensate for the lower voltage durring cranking the engine. The set up he describes has a solenoid relay, (typical Ford set up), and in this case the second small terminal on the solenoid relay will be the resistor bypass terminal.

Rick,
LOL...no sweat, its all good info

Dave,
I guess I should have gone back and reread the original post...sure enough he tells what he's got. It's been awhile since I was messing around with a Ford starter solenoid, I was just trying to remember how I used to hotwire them....lol. A short run of wire from the battery terminal to the ign feed terminal a quick jumper across the battery terminal to the ignition terminal and away you go....(I ruined several pocket knives as a teen hotwiring Dad's truck....oops)

Bobby

Pictures are always good. This is what everybody is describing:
https://www.ford-trucks.com/user_gal...142899.520.390

Hmmm That would do it. I had a box I made with switches on it and pigtail leads with aligator clips on it that I would hook up on the backside of the ignition switch. It's a wonder I never got caught.

Happy Daz' ...

Tfagerholm see Randy Jack's picture above its the same as the one I have just on a sheet of paper.

Looks good
 

The wiring kit I put in was a Painless one... not sure where I put the cursed diagram though. It's been a long process if you know what I mean. Thanks to you all for the input. I appreciate it. I'm gonna give it a try this weekend... I'll post results on this thread.

It ran a couple of years ago but has sat since and I haven't been around the storage site to keep it up. I hate it when things start regressing. I'm not sure I ever had it wired correctly anywhoo. I know the coil was an old one I bummed off another motor (could have fried it) also the cap and rotor now have a good white crusting on the contacts. I'm putting in new cap, rotor, solenoid, coil, points, and this time a ballast resistor. Didn't find out about that one last time.:-banghead

Next step will be figuring out how to correctly drop volage for the guages. I built voltage reducer from an older article in a Hot Rod magazine. But I may just switch to what Ford did in 56. Looks like some good posts on here since the last time I messed with it. That should help.

Anyway,:-blah
Thanks All

Yea, I hate it when life starts interupting. Heck, I haven't touched my truck in months (and its driveable). It will probably take me a day of escavating in the garage to dig down to it (isn't it amazing how much stuff can get stacked on an old truck...LOL)

You can buy ready made voltage reducers at the parts stores. I think Ford used them on dash gauges on most of their vehicles all the way up through the mid 60's. I know the NAPA carries them but I can't remember the part #

Bobby

I've got a follow up question for you masters of the ignition system. When converting from a + ground to a - ground, do you need to switch the wires in the distributor (connections to the points)? I've got my 49 running but am seeing my voltage (measured at the battery, no alternator hooked up) jump up to about 20V at just about the same intervals i would expect the cylinders to by firing.

How the points themselves are wired shouldn't make a difference between + ground and - ground. The points are a basically a switch that open and closes a path to ground regardless if the system is + ground or - ground.
An ignition coil is a transformer and needs to be wired correctly but the points are a basic switch.

The battery voltage jumping to 20V on a regular basis is odd but probably not conected to the ignition system. You probably wouldn't be able to see the points operating with a meter, they move pretty fast. Consider this, each revolution of the engine the points need to open and close once per cylinder, so at an idle of 600RPM mulitplied times # of cylinders + a whole lotta opening and closing.

I'd look more at your charging system for the regular jumps to 20V

Bobby

thats the funny part, the alternator isn't even wired into the system yet... :)